To set up GPS on the TYT-390, make an own contact with name GPS and call ID 5057
Then set up Destination ID: GPS under GPS settings. Set the interval to 60s or more. (Not too often as GPS packets take repeater capacity)
Now select “GPS system 1” under the channels you want GPS enabled on. I have made a set of channels with GPS on and a set of channels with GPS off.
In Brandmeister dashboard, go to Services/Self Care and select chinese radio. Check that your call and your name looks OK (you need an account at Brandmeister).
Then program your radio with the codeplug with the radio settings above.
Set your radio outside for several minutes to achieve GPS lock (can take quite some time).
You should see a globe symbol show up without the red ring (red ring means no GPS lock).
Then you can check aprs.fi for your callsign.