Custom Payment Method in payment_details for Create Invoice API

Hi, I'm trying to create an invoice with custom payment method

url:
https://api.sky.blackbaud.com/accountspayable/v1/invoices

payload:

"vendor_id": "5600",

"amount": "99.0",

"description": "BB-20201104",

"invoice_number": "7500000079",

"approval_status": "Approved",

"due_date": "2020-11-04T07:34:26.568+0000",

"payment_details": {

"remit_to": {

"address_id": "79132"

},

"payment_method": "AP_DOCUMENT" //custom payment method

Per API docs https://developer.blackbaud.com/skyapi/apis/accounts-payable/entities#InvoicePaymentDetails only four existing methods can be used. Can we pass custom payment method or create them before hand, before invoking create invoice api ?


Thanks.