Service development

I want to develop service thet will send every 10 minutes get request.
i want the user start the app once, and from there the service will work and send post every 10 min between 08:00 and 18:00.

(Of course the client knows about this, I want to make it easier for him in general so that he doesn’t mind having an application in the background (like Google that always runs in the background and knows how to calculate a route, like Facebook that listens
Like WhatsApp that also listens, etc.)

thenks