Use UI Button for GetButtonDown("Jump)"

What's up, guys, I am having a bit of a hard time figuring this out. I've done a platformer prototype in which I want to implement touch controls for Android/iOS. The thing is that I just want is for the button to "replace" the GetButtonDown("Jump") and for it to work in the same way (a tap makes the player jump a little, holding it makes the player jump higher) and I absolutely have no f*cking clue of how to do it. Youtubers' tutorials are pretty much outdated. Oh, and I also installed the Input System which apparently comes with Touch support for the bindings but I can't find any tutorial of how it works either.

I'm pretty new to programming so I would appreciate some patience lol and if my english gets a little funny at some points is because it is my second language.

p.d: It won't help me if you just post the link to some Unity manual, I can find those myself. I need help understanding them.

 

Please, close this, I already figured this out. Thanks anyways