When you enable the exchange with other products option, it is required to connect a payment gateway in order to collect the difference amount between two products. Return Prime is integrated with Stripe in order to help you with this.
Please find the below steps to connect to the Stripe account.
1. Click on the "Settings" icon available on the bottom left corner.
2. Please navigate to the "Integrations" settings.
3. Scroll down on the page and you will find "Stripe" integration. Click on the activate button.
4. On this page, you will need to provide the publishable key and secret key. This article from Stripe can help you locate the keys on the Stripe dashboard.
Once it is activated, Return Prime will capture the difference amount between two products before the customer submits the request.