I want to put my stream there, but I don't know how to do it. I'm a noob in streaming.

Just stream and twitch and it appears. Although it is hidden by default if you don't have a PB in that game, it's also not visible if you put "[nosrl]" in the title

Thank you then

And make sure you have "Appear on streams page while streaming" ticked in your settings.

what do you meen by not having a personal best in the game? sorry if i sound stupid i am quite new to this aswell... like. my first speedrun was yesterday

Personal Best aka PB is your fastest time in your selected game.