Javascript put a variable into a regex?

Question

I have a text from a message in a varaible:

const text =
        "I don't know @Dondes but it did.  It's the highest scoring game in history.";  

I have a regex to check the mention of a name: let regex ="\@\Dondes\b"

I would put the name to check into a variable and use it in the regex like this:

let test = "Dondes";
const userName = `\@\${test}}\b`;  

And after that keep the name like that:

text.match(userName)

But it didn't work ^^ How can I do that?