# addCustomerCreditSourceToCheckout
Use this global method to create a customer credit payment source and attach it to checkout.
The [payment session](https://docs.digitalriver.com/digital-river-api/integration-options/checkouts/creating-checkouts#payment-session) identifier and [currency code](https://docs.digitalriver.com/digital-river-api/integration-options/checkouts/creating-checkouts/selecting-a-currency#how-currency-is-prioritized) will be derived from the cart if multicurrency is enabled in org. Otherwise, the currency code will be derived from the user’s default currency.
Before creating a payment source, use this method to verify that the `amount` specified by the shopper is less than or equal to the `amountRemainingToBeContributed`. If the amount passed into the method is greater than `amountRemainingToBeContributed`, it will throw an error.
This global method will set the `amountContributed` and `amountRemainingToBeContributed` values in the [`Cart` object](https://docs.digitalriver.com/salesforce-lightning/salesforce-lightning-b2b-commerce-app-2.1/appendix/custom-fields-and-objects#cart-standard-object).
## Sending a request
This method accepts parameters in JSON string format and can be called outside the managed package. You need to pass the `cartId` and the `amount` applied to this method.
| Parameter | Required/Optional | Determine |
| ------------- | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `cartId` | Required | The Salesforce ID for the `cart` object. |
| `amount` | Required | The amount specified by the shopper to use for the customer credit source. |
| `paymentName` | Optional | You can pass the paymentName if you want to provide a different label (for example, GiftCard123) for the payment on the payment detail component. The paymentName appears in the Display Name field for a DR\_Transaction\_Payment\_\_c object.
If this parameter is not provided, the label "CustomerCredit" will be used by default.
|
{% code title="Request body example" %}
```json
“{
"cartId":CartId,
"paymentName": "GiftCard123",
"amount”: "50",
}”
```
{% endcode %}
## Receiving a response
You'll see the following parameters in the response.
| Parameter | Description |
| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `isSuccess` | This global method returns a Boolean value where:
true–indicates the source was successfully created and applied to checkout.false–indicates an error occurred while creating or attaching the source to checkout. The system returns an error message when an error occurs, and the Boolean value is false.
|
| `errorMessage` | If the system returns an error and the value for isSuccess is false, this parameter displays one of the following error messages:
- Missing or invalid input parameters specified: One of the input parameters are missing or invalid.
- Invalid amount specified: The value specified for the amount is invalid.
- DR API error: An error message that comes from the Digital River API.
|
| `sourceId` | The unique identifier of the customer credit source. |
{% code title="Response body example" %}
```json
{
"isSuccess":{{boolean_value}},
"errorMessage": {{error_msg}}, //in case of error
"sourceId":{{sourceId}} //in case of success
}
```
{% endcode %}
## Calling the global method from a custom component
Import the `addCustomerChreditSourceToCheckout` method into your custom component javascript file with `digialriverv3` as the namespace as shown below.
{% code title="Import example" %}
```javascript
import addCustomerCreditSourceToCheckout from
"@salesforce/apex/digitalriverv3.DRB2B_CustomerCreditService.addCustomerCreditSourceToCheckout";
```
{% endcode %}
Call the global method from a custom JavaScript file by passing the `cartId`, `amount`, and (optionally) `paymentName` arguments as shown below.
```javascript
handleAddCustomerCredit(event){
addCustomerCreditSourceToCheckout({
inputData : JSON.stringify({
cartId : this.webcartId,//cart Id
amount: amount
})
}).then((result) => {
// implement logic here in case of success
})
.catch((error) => {
// implement logic here in case of error
});
}
```
---
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