Let us use variables in the popups for button confirmation text

Currently, if you have a button with a Confirmation text popup, you have to include static text

This seems a little restrictive. It would be great to have the ability to include variables in this text, in the same way you can use variables in the button text.

Being able to say “You’ve told us you submitted X/Y/Z, are you sure?” reads a lot better than “Are you sure what you’ve told us is correct?” for front end forms, and it would make them more screenreader friendly, by giving context to the content of the popup.