Suspect it's coming in the next server release.. hint is in the code: https://github.com/traccar/traccar/commit/517382ccc972d6d1ba2b5fd2d912cc6e5ac83902
if you're happy to compile from source then you should be able to get it once the commit passes.
Not in any hurry, just assumed 4.0 would have already had the core written into it. Unusual approach releasing apps to store without mainstream server being available.
Mobile apps are subject to Google and Apple approvals, so to avoid any issues in future, I decided to publish them now.
Forward thinking very good sir :)
How do we configure push notifications on android? Struggling to see any change as of yet. Many thanks