Hi,
Usually terms of payment is available in the billing document at the pricing data in header level ( VF03).
If you want to use the FM RV_BILLING_PRINT_VIEW to get the payment terms! Need to pass the communication structure as below. ( BILLING DOC NO AND SPRAS)
The program is extracting the payment term from the billing document and getting the text from TVZBT table. Based on the payment key and language getting the description. Check and debug the program as per your requirement. Check the results below!
Kiran