Applying credit to invoice

Self-Hosted | v4/Legacy
1

I’ve searched the forums and can’t seem to find an answer to my questions.

I’ve created a credit for a customer. Then I created an invoice.

Two questions:

  1. How would I apply that credit to an outstanding invoice?
  2. How could my customer apply that credit to an outstanding invoice from his Portal?

Thanks,
Rick

2
  1. Create a payment and select “Apply credit” as the payment type
  2. It isn’t supported