whenever I do /dynmap webregister I get an error, "Login support is not enabled" "[02:25:55] [Server thread/INFO]: Login support is not enabled"

v3.5
1.19.3
minefort
I

it happens every time I do the command, I have done the command 10+ times

You need to enable login in configuration.txt, after which it will work.

Assumed fixed, closing issue