Hi @LoneTreeLeaf

Thank you for your suggestion.

The solution I found for now (although I hope @LeonidS 's answer will help me find a better solution), is to modify the "View Ad" page as follows:

1) I configured the "Ad Text" block to be not visible to unauthenticated users.

2) I added an HTML block with a message for unauthenticated users that says you must log in or register to see the ad.

I think it is not the ideal solution, but in principle it works for me.

Regards.