Selfhosted Headless Nextjs frontend - Trouble with redirects

Environment: Nextjs frontend hosted on Vercel; Ghost headless hosted on Digital Ocean

Next url -
Ghost url (this may be a problem?)

Ghost-CLI version 1.16.3

Ghost installed 1-Click on Digital Ocean - followed documentation for configuration for Mailgun; use Lab for yaml files for redirects/routing

Node version 12+ (maybe that is an issue? I am finding some stuff on Nextjs installation breaks on higher Node version…)

Normal Digital Ocean database (MYSQL)

OS & browser are you using? - normally work on iMac in Firefox / when doing Digital Ocean stuff it’s ubuntu

Just irratic / odd redirect locations.

My redirects.yaml file
I started with:
/: /

What I want – When I send email newsletter from Ghost, the post lands in mail as expected. When click on “View Online” - takes user to version of post.

I expect that I have some more learning to do around Mailgun / etc

In the meantime, though, I though to do a redirect so that the post would always show up on the site.

To be honest, I am willing to settle for a different page – anything, just on the site not site.

The behavior I got when I tried:
/: /
what I needed:

Thank you! Happy to pay it forward, Thank you!