I am currently working on an android chat app with targeted api 30.
The thing is that if the user send a message to any other user than if the network is available than the message is delivered at the instant to the receiver, but if at that moment internet is not available to that app then that message is stored just like Whatsapp Undelivered messages, so that whenever internets is back again then that messages could be retried to send.
I already investigated about it on Google and stackoverflow and found about Workmanager, but I want to schedule immediate tasks so that along with gurantee of work completition, time constraint is also followed.