The たい grammar point explains how it can be used for “I” or “you”.
たい | Japanese Grammar SRS
[たい belongs to a group of ‘personal’ adjectives, that is used to describe the speaker’s/writer’s wishes/desires (first person) or the listener’s wishes/desires (second person)]
[If you want to describe someone else’s wish/desire (third person) you have to use the「verb[stem]+たがる」construction or indirect speech 「verb[stem]+たいと思う」]
If you were describing “he” or “she” or “they” or another third person, then you would use たがる.
どんなに押したくたって、この赤いボタンを押してはダメ。
No matter how much you want to press it, you must not press the red button.
Also, the English sentence is using the “general” you not the “specific” you, where the speaker is not necessarily talking specifically about the listener. You could replace “you” with “I” or “one” and it would have the same intended meaning – any person should not press the button.
e.g. No matter how much one wants to press it, one must not press the red button.
If it helps any, I think of たい as turning a verb into a feeling (of wanting). It’s used like an い-adjective. Just like you can say うれしいですか or さびしいですか about your listener, you can use 行きたい or 押したい about your listener too.