Timer run in back ground

Hi out there.
I hope someone can tell if and how it is possible to have a timer to continuo running in the background if the phone rings or you jump to a nother app without shotting down the app???
I also need this to work in the classic version where I have an app where this also is a problem.

Can somebody please help me n this issue.
Please please…


It is impossible to implement in Thunkable X.