Yes, I was reading the above instructions on wiki but it is a bit confusing and complicated.
I finally managed to set up PayPal correctly and I managed to enter correct credentials to
my account on our page and Admin account as well.
The settings in /page/payment-details can be confusing especially for "standard users" or users
that are not very skilled with those kind of things.
What confuses me is the two PayPal settings:
It is confusing to me, not to mention the users of the site - how to explain to them what data (credentials) to enter and where, to which field and where
to get those credentials in the first place....
So it would be great if the wiki would tell us something like this:
Admin must enter this and this and the credentials are obtained like this and this.
Other non admin users need to do this and this.