How to block URL redirects using GoogleDomains

On Google Domains, I have www.example.com. I also have free hosting of www.university.com/~myname.

I hope to be able to forward
www.example.com to www.university.com/~myname,

But I want the domain to still appear as www.example.com.

I want it too

www.example.com/something/something.txt

Forward to

www.university.com/~myname/something/something.txt,

The URL still shows www.example.com/something/something.txt.

How can I do this?

(I know this question exists, but the settings page is out of date: How to block a domain from Google without the Google app)