You can look at this thread: https://www.speedrun.com/the_site/thread/1gbee

The TL;DR: this site is built for tracking speedruns, not highscores. Tracking highscores will require developing an entire new system, and that doesn't belong on this site. There are few games here that are built around highscores, like https://www.speedrun.com/flappybird . They handle highscores by submitting the score as milliseconds and seconds, with time sorted by descending order. This is a hacky way to handle it, and highscore-based games are not accepted to speedrun.com anymore.