If you find the Ubisoft Connect remaining running after you quit the game as infuriating as I do, you can use this launch option to automatically quit Ubisoft Connect after you exit the game:

bash -c 'sleep 30; while pgrep -x "MainThread" >/dev/null && pgrep -x "upc.exe" >/dev/null; do sleep 1; done; pgrep -x "upc.exe" >/dev/null && killall upc.exe' & %command%

This command monitors existance of the Trackmania's own process, and once the Trackamania's process ends, it also ends the Ubisoft Connect process.
If you have a slower PC or a Steam Deck, you may have to increase the sleep 30 to sleep 45 (the number determins how many seconds to wait) or more so that the command does not kill Ubisoft Connect before the game even launches.

However, this is all entirely optional, and if you don't mind manually quitting Ubisoft Connect, you don't have to use this launch option.