How to allocate bank payment to customer credit note

Hello jennifercusters, thanks for joining the Community 

It isn't possible to match credits to bank transactions as these are non-posting (i.e., they don't have a payment account assigned).

If the payment in the bank is to show as credit on the customers account, you can instead delete the credit note and post this directly from the For review feed. To do this, click on to the transaction to expand, select the customer on the Supplier/Customer drop-down and set the Category to Debtors (or Accounts Receivable). 

The credit can then be linked to a future invoice payment (select Receive payment on the invoice > Tick the transaction under Credits to apply).