@Muzirian Pre open a URL in the app and nothing else can be opened other than that URL.@Muzirian Like this
https://play.google.com/store/apps/details?id=de.ozerov.fully

Is there an FOSS android app that takes an URL and shows it in kiosk mode?

https://social.thej.in/o/132a536a036c4fe880be0df91262d694