HTTPS for apps - How do I add new apps to repository?

Hi All,

New homelab user - not very tech savy - decided to go with ZimaOS.

Trying to open Thunderbird but I get this error:
Error: This application requires a secure connection (HTTPS). Please check the URL.

My HTTPS is turned on from the ZimaOS Settings –> Developer View – however I believe this just secures the Dashboard.

How do I secure the apps like Thunderbird so I can get it to work? I read online it’s got something to do with a reverse proxy sitting in the middle and redirecting the apps to a non-secure route. Nginx Proxy Manager was suggested but I don’t see it appear on my appstore. Is it possible to add this as a new repository? If so, what’s the URL for this? I see lots of apps on github but when I copy and paste the github URL it gives a ZIP error.

Would appreciate your help!