The Create Refund endpoint allows you to initiate a refund based on a completed PaymentIntent. Once the refund is successfully created an email is sent to the end-user's address in order for them to provide destination address for the refund.

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Partial Refunds:
To create a partial refund, use the optional amount request body paramter.
The total of all created and completed partial refunds may not exceed the original Payment Intent amount. If the amount parameter is not provided, the API assumes the full refund is requested. If other refunds have been created earlier, not providing this parameter will initiate a refund of the remaining payment intent amount.