http://srqzezgrcqbequac733i3fej7d2cymzdiy5biie46tpib3ii7mfxfcad.onion/current.php
With normal GPS trackers which you can track on your cell phone, there are sim cards inside which can usually be clearly assigned. I think that my solution is the “safest” because you don't need a sim and no accounts and they are customizable. the disadvantage is that it is more complicated and costs more and you have to be in the vicinity regularly.