Background
Before starting this tutorial, make sure you understand the following topics from the Quick start section: Sandbox environments (especially about testing). Authentication (about authenticating using your API user and when you need a login versus a one-time-use token).

You may want to authorize a transaction (auth only) and capture it at a later time.

Please note that auth only transaction(s) are currently only available through the following alternative payment methods (APMs):

Afterpay through Citcon
ApplePay - multi and individual iframe only
GooglePay
Klarna - multi and individual iframe only
PayPal - custom redirectUrl only
PayPal (with Braintree) - individual iframe only
SEPA through Adyen

You can run an auth only transaction using any of the three integration methods, depending on the payment method:

Multi Iframe (Express APM) for Auth Only
Button Iframe URLs for Auth Only
Redirect URLs for Auth Only

Multi Iframe (Express APM) for Auth Only

To run an auth only transaction using the multi iframe (also known as Express APM), follow the steps below.

Prepare Your Checkout Page

Follow steps 1-2 of the Express APM tutorial.

Request an Express Iframe URL

Follow step 3 of the Express APM tutorial.

Include isAuthOnly: true in the body of your request.

If the APM supports it, you can also include Pay Later messaging.

curl -X POST https://api.nexiopaysandbox.com/apm/v3/token \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'Authorization: Basic [Base64_encoded_login]'
  -d '{
  "data": {
    "amount": 4.00,
    "currency": "USD",
    "customer": {
      "orderNumber": "12345678",
      "firstName": "John",
      "lastName": "Doe",
      "email": "[email protected]",
      "billToCountry": "US"
    },
    "totalTaxAmount": 0,
    "cart": {
      "items": [
        {
          "item": "E200",
          "description": "Platinum set",
          "quantity": 2,
          "price": 2
        }
      ]
    }
  },
  "customerRedirectUrl": "https://[your-ecommerce-website]",
  "uiOptions": {
    "displaySubmitButton": true
  },
  "isAuthOnly": true
}'

A successful response includes the expressIFrameUrl. Copy or store this for use in step 3.

{
  "expiration": "2021-07-22T20:49:50.000Z",
  "token": "830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "asyncTraceId": "830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "expressIFrameUrl": "https://www.api.nexiopaysandbox.com/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "redirectUrls": [
    {
      "paymentMethod": "klarna",
      "url": "https://api.nexiopaysandbox.com/apm/v3/popup?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=klarna"
    }
  ],
  "buttonIFrameUrls": [
    {
      "paymentMethod": "klarna",
      "url": "https://api.nexiopaysandbox.com/apm/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=klarna"
    },
    {
      "paymentMethod": "braintreePayPal",
      "url": "https://api.nexiopaysandbox.com/apm/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=braintreePayPal"
    }
  ]
}

Complete the Payment Process

Follow steps 4-6 of the Express APM tutorial.

A successful auth only transaction returns a status of authOnlyPending or authOnly.

Individual Iframe (Button URLs) for Auth Only

To run an auth only transaction through an APM using the button iframe URLs, follow the steps below.

Prepare Your Checkout Page

Follow steps 1-3 of the Button Iframe URLs tutorial.

Request the APM Button Iframe URLs

Follow step 4 of the Button Iframe URLs tutorial.
Include isAuthOnly: true in the body of your request.

If the APM supports it, you can also include Pay Later messaging.

curl -X POST https://api.nexiopaysandbox.com/apm/v3/token \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'Authorization: Basic [Base64_encoded_login]'
  -d '{
  "data": {
    "amount": 4.00,
    "currency": "USD",
    "customer": {
      "orderNumber": "12345678",
      "firstName": "John",
      "lastName": "Doe",
      "email": "[email protected]",
      "billToCountry": "US"
    },
    "totalTaxAmount": 0,
    "cart": {
      "items": [
        {
          "item": "E200",
          "description": "Platinum set",
          "quantity": 2,
          "price": 2
        }
      ]
    }
  },
  "customerRedirectUrl": "https://[your-ecommerce-website]",
  "isAuthOnly": true
}'

A successful request returns an array of buttonIFrameUrls. This array is a list of all APMs currently enabled on your merchant account. Copy the url associated with the wanted payment method.

{
  "expiration": "2021-07-22T20:49:50.000Z",
  "token": "830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "asyncTraceId": "830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "expressIFrameUrl": "https://www.api.nexiopaysandbox.com/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "redirectUrls": [
    {
      "paymentMethod": "klarna",
      "url": "https://api.nexiopaysandbox.com/apm/v3/popup?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=klarna"
    }
  ],
  "buttonIFrameUrls": [
    {
      "paymentMethod": "klarna",
      "url": "https://api.nexiopaysandbox.com/apm/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=klarna"
    },
    {
      "paymentMethod": "braintreePayPal",
      "url": "https://api.nexiopaysandbox.com/apm/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=braintreePayPal"
    }
  ]
}

Complete the Payment Process

Follow steps 5-7 of the Button Iframe URLs tutorial.

A successful auth only transaction returns a status of authOnlyPending or authOnly.

📘
Note
If the customer selected PayPal (with Braintree) as the payment method, then, in the event posted to your window, the response includes an apm.token parameter. Save the apm.token value somewhere in order to use it again (probably similar to how you save TokenEx tokens already).

Redirect URLs for Auth Only

To run an auth only transaction through an APM using the redirect URLs, follow the steps below.

Prepare Your Checkout Page

Follow steps 1-2 of the Redirect URLs tutorial.

Request the Redirect URL

Follow step 3 of the Redirect URLs tutorial.
Include isAuthOnly: true in the body of your request.

If the APM supports it, you can also include Pay Later messaging.

curl -X POST https://api.nexiopaysandbox.com/apm/v3/token \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'Authorization: Basic [Base64_encoded_login]'
  -d '{
  "data": {
    "amount": 4.00,
    "currency": "USD",
    "customer": {
      "orderNumber": "12345678",
      "firstName": "John",
      "lastName": "Doe",
      "email": "[email protected]",
      "billToCountry": "US"
    },
    "totalTaxAmount": 0,
    "cart": {
      "items": [
        {
          "item": "E200",
          "description": "Platinum set",
          "quantity": 2,
          "price": 2
        }
      ]
    }
  },
  "customerRedirectUrl": "https://[your-ecommerce-website]",
  "isAuthOnly": true
}'

A successful request returns an array of redirectUrls. This array is a list of all APMs currently enabled on your merchant account. Copy the url of the APM you want (for use in step 3).

{
  "expiration": "2021-07-22T20:49:50.000Z",
  "token": "830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "asyncTraceId": "830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "expressIFrameUrl": "https://www.api.nexiopaysandbox.com/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2",
  "redirectUrls": [
    {
      "paymentMethod": "klarna",
      "url": "https://api.nexiopaysandbox.com/apm/v3/popup?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=klarna"
    },
    {
      "paymentMethod": "payPal",
      "url": "https://www.api.nexiopaysandbox.com/v3/popup?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=payPal"
    }
  ],
  "buttonIFrameUrls": [
    {
      "paymentMethod": "klarna",
      "url": "https://api.nexiopaysandbox.com/apm/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=klarna"
    },
    {
      "paymentMethod": "braintreePayPal",
      "url": "https://api.nexiopaysandbox.com/apm/v3?token=830d36f6-a5e3-4455-9600-3a55b63e2fc2&paymentMethod=braintreePayPal"
    }
  ]
}

Complete the Payment Process

Follow steps 4-6 of the Redirect URLs tutorial.
A successful auth only transaction returns a status of authOnlyPending or authOnly.

Multi Iframe (Express APM) for Auth Only

Individual Iframe (Button URLs) for Auth Only

📘Note

Redirect URLs for Auth Only

📘
Note