Using Angeleyes excellent Permissions tutorial and code, I have managed a small developer site, that can get Access Token and Token Secret. From there Im clueless, Paypals' Github claims a CreateInvoice sample, which doesnt exsist, and much searching i have learned(?).
You need to include your app credentials, your API username and API password, and in an added "SUBJECT" line the ... payer_ID merchant/payer email...
(conflicting info exsists here) to run another API you have permission to execute.
None of this is very clear for me. All tutorials end with the access code and Token secret.
I am attempting to add a buy now button that sources the MERCHANT from DB (multi merchant) but am getting nowhere overcoming this conceptual gap.
How do i mesh Permissions API with ExpressCheckout API? (step by step if possible)
Edit:
Search continues also, how does one recover from the permissions granting api methord the merchant email for subject?!
PayPal updated their description DURING the grant permissions screen, to mention Pal Id access..
Now going to open a new question, to find out how to use a saved Permissions Token and Secret in php to USE the access token and token secret to get pal ID.
hope this helps someone else :)