PayPal using Katalon OAuth2

Archive
,
1

Dear Expert,

I am working on PayPal using Katalon for Restful API:
https://api.sandbox.paypal.com/v1/invoicing/invoices?page=3&page_size=4&total_count_required=true

I noticed it is much more complicated as it has to Comply OAuth2, with that I need to try to guess if it is

  1. Password Credentials
  2. Client Credentials
  3. Refresh Token
  4. Authorization Code.

Could someone teach me how to identify if PayPal architecture is following which method? Kindly advise.

Best regards,
Tiong