Adding a Paypal button to the site.
 

I have added a donation button to my site, but when I try to use it, it sends me an Error from Paypal. The button is added to a module besides the forum, and it's doesn't working.

They said "We can trust on the ID".

So, I went to my paypal account and got the new code and tested and same issue.

Is there a guide to add a good module to put a Paypal button ?