Send a confirmation e-mail on Google Forms to my respondents with the edit form link?

I've been playing around with scripts all week and it just doesn't seem to be working and I don't know why. The first thing I've been trying to do was send a simple confirmation e-mail with text. I can't even seem to get that going. I was using this tutorial: https://www.youtube.com/watch?v=GuFZ78_NZtQ

But what I really need for the edit link to appear in the confirmation e-mail to the respondents. I know it was once impossible but I saw on another Stack Flow page that it's now possible.

(How to add "Edit Response" link to Google Forms emails?)

Can anyone help me out?

Thank you!