Go to [https://www.xero.com/](https://www.xero.com/) and log in to your Xero account.
Click the “Add Payment Service” button.
Select the payment gateway you would like to use from the list of available payment gateways.
Enter the required information for the payment gateway, such as your merchant ID and API key.
Click the “Save” button.
Click the “Activate” button to enable the payment gateway.