You don’t need a paid account to do this…free account will work just fine.
But for the not “technically inclined”…you can get Spike app and it has the same reset command built in for iPhone users. So you can just use the spike app to reset and then go back to using dexcom app as usual. You’d have to unpair the transmitter from the phone in order for the transmitter to connect with each app, but not a huge deal. Just unpair from phone before using Spike, restart phone, pair in Spike, reset the transmitter, unpair from phone again, restart phone, pair in dexcom app.