I recently started using Joplin Self Hosted and Joplin App on iOS, Linux and Macos as well as Windows with Encryption and love it so useful.
However there is a feature I would love and that's to have support for Passcode / Password unlock in the apps, Would this be possible as I think it would be a great feature to add to Joplin.
On iOS there's the option "Configuration/Use Biometrics", but that's in beta mode as yet. For the desktop apps, there's no native option to lock them, although there were passionate discussions about the lack of this feature on this forum.
Can't find a specific link, but it all boils down to this: Any user interested in locking up the app's data should do so using methods provided by the specific OS (such as separate user accounts or full drive encryption).