Assigning keyboard shortcut to highlight selection

I think this has been asked before, but I think I still need help. Similar to, say, CTRL-B makes selected text bold, is it possible to (if so how) to assign keyboard shortcut to make selected text highlighted? (Between SELECTED TEXT).

If you mean the red highlighting and gray background, then you can do this with Ctrl+`.

You can find that in the shortcut menu (?), but I see I’ve confusingly named it “Red inline code selection” :roll_eyes:.