Thunkable can’t run processes in the background but I believe there’s a way to still do what you want by comparing the time when the app last ran (in foreground) and the time it was re-opened.
I’ve been working on this (see this post) but I got stuck with a loop/wait bug. I think that’s working now so I may be able to figure out a method for this soon.
@mom7667yafy Said they figured out a solution: Can I make an app that alerts the user of the time to review?