One customer is unable to install app through link

Hi all, we are distributing our confluence app to customers through sharing a link.
It has worked for several users but one particular customer is running into error:
“Looks like your app isn’t configured for the right atlassian products”

Any idea what could cause this error. The installation wizard already looks for and picks confluence sites that user has admin access to.
So given that’s already true for the user, what else might a customer need to install a forge app successfully?

Stuck on this one. Nothing comes up on the internet when I search with that string and I am unable to reproduce this error.

Could it be that the customer is on-prem or on data center? What error will show up for those cases?