Text boxes are just text. No HTML in there.
You want to do Actions on a sheet.
I created a dummy sheet that displays the same text as you listed. Only I added dashboard actions on it. One is a hyperkink action that opens Google. One is an action that effectively does nothing, but that's how you control what it will do. Click on the text and see what happens.
Don't worry if you get an upgrade message when you open it. I created it in 8.2 so that no matter what version you are using, it will upgrade to your version when you open it.
Action example.twbx 10.1 KB