Where to put the planet file of ZTnet private root server on a Teltonika RUTX50

I created a private Zerotier root server (planet). I need to copy the generated “planet” file into the router (it should be persistent). I only find a “planet” file under /tmp/lib/zerotier-one_21d72bd151_2#. But it is overwritten when I switch the interface off and on (which has to be expected for a temp file).
Where is the proper location for this file?
Or is there a better way to solve my problem to get a faster (relayed) connection between a Teltonika router behind CGNAT and a Mikrotik router with a fixed IP.