Bought and installed VPN Premium now nothing works

Today, I bought VPN Premium. During the installation, I was asked to uninstall all Bitdefender products (Antivirus and the basic VPN). When I did that, the new VPN apparently installed (although I had to enter my computer password several times, a confusing and frustrating "feature"), only to have the new VPN tell me that I needed to give access within System Preferences. I have tried and tried, but do not see what I am supposed to do. And for everyone asking; yes, I rebooted my Mac afterwards, and keep trying to follow the instructions. There is nothing that works! So I am ready to delete everything Bitdefender and ask for a refund. Any advice?