How many devices does the non-google-play app support?

I’ve tried searching the community and documentation without a viable answer.
I understand that when downloading from Google play, the license is tied to the account which allows for multiple devices to use the app. What about the one activated with a license key?
Thanks in advance.

It’s the same with the license key. This license is bound to the person who bought it but can be used on any number of devices owned by that person.