I have been searching all this while and couldn't really find any documentation which tell, why one should use express checkout or REST api?
Can someone please tell me the difference between these?
I need to implement online payment gateway for user to purchase a plan and then continue using the application online (more like a service).
With express checkout I found 'Physical' and 'Digital' item categories. I am not providing any goods to the users ( no online store in my app ).
What should I choose? Please help.