When i was learning opencart and i was trying to setup paypal integration with sand box then i fetch one error. Every thing was working proper but when i try to pay money i found error like as bellow:
this merchant is not enabled for auth/settle
I did also try to change my buyer account and try but same, I also did try with different way but same result.
At last i found that i used
Personal account on opencart module setting, we require to use Business Account. So when you create new user then select Business in account type option as like bellow image.