Video doorbell not working

I have a Simplisafe system that I purchased about 4 years ago. This year, I decided to add on the video doorbell- however, I cannot get the app to recognize the doorbell when I want to add it to the system

The tech support line was not very helpful when I called - they said they didn't have any ideas once we went through the basic setup.

Have others had the same problem, and if so, what was the cause?

I'm on my last resort here - going to get rid of the system and get Ring if I cannot get this to work.

Thanks