Mr. Paolo, I did what is instructed in the documentation. The problem is the message I am getting after I select any of the first 3 options:
PayPal Standard
Authorize.Net (AIM)
Worldpay
The message is the same for the 3 of them
“Important: Payment Gateway(s) PayPal Standard are in testing mode and will not receive real payments. Go to Gateway Settings”
see image attached