so my updated function is good i think

Your function do not respect Android components lifecycle. If you want to use it on android would be better to cancel coroutines on destroy (or other lifecycle event)

as you said that Cancel coroutine at onDestroy ,does this means coroutines are running after doing its task ?

Your coroutine will end in your code sample, but only after the delay you specified. So, for example, if your delay is set to the equivalent of 10 minutes, then user navigates away from that activity, if you don't cancel the coroutine then your

work.invoke

will still execute after the 10 minutes are up.

ok i understood ,thanks

Coroutine itself will be collected by GC when work (everything inside coroutine) is finished, but only after that. If you cancel coroutine it also cancels nested coroutines (if coroutine uses the same job, or just supports cancellation like

delay

), also canceled coroutine automatically prevent invocation of next suspend function call