Get Variable to link

Hi there !

I got a little problem… Let me explain.

I create manually for each user of my website a private page that he and only he can see.

The addresses of the pages are created as is “https://exemple.fr/private/didier” Didier is the name/username of the user.

I wish I could include a button on the site (in a page) that will redirect the person who clicks a link:

“https://exemple.fr/private/$username”, “username” is replaced by usersame user who clicked.

So if Didier click on the button: “https://exemple.fr/private/$username”
the redirect link will be for him
“https://exemple.fr/private/didier “and if Geraldine clicks this link, it will be redirected to “https://exemple.fr/private/geraldine.”

So I know that in theory i should create a function in PHP that will get $username (or equivalent) in the database and associate it with a keyword (or shortcode?) So in theory it would give something like :

[username] = Retrieve: “BDDUser/$username”

In theory, huh, I’m not a programmer I just have some basics bases. p

And then if I make a link to an image, or other button on the site that would “https://exemple.fr/private/%5Busername%5D” still theoretically it should give the function I want.

The trouble is that, as I said, I know not program and I have no idea what to do so rather than do something stupid I just ask a boost!

I hope I was clear enough!
Thank you! ??