Minecraft door with command block?

I would like a door to be opened only when person x steps on the printing sheet. How does it work? (i.e. With commands…)

There are YouTube videos for it.

Here, is pretty well explained, apparently

OK thanks

But it doesn't show how to limit it to one person

Oh, that should only work through a certain person. Maybe I'll find something. You just have to refer to the name of the user. Never did something like that myself

Don't you just have to refer to the player first with @player name and then write the command after it? This will probably always work for you because you are the owner. But otherwise only with the player whose name is there. As I said, I never tried it myself, I can only speculate