Hello Matthew,
You can't point to an A record (ip address), because we don't have a unique ip address! All websites are served by AWS Cloudfront with a pool of 4 millions of IP addresses...
For that reason it's not possible to point to 1 ip in particular ...
But to connect your external domain without transferring it to us is still possible, please check our guide here:
https://support.appdrag.com/blog/61-External-domain.html
When this is done, you can also follow this second tutorial to activate SSL on your external domain:
https://support.appdrag.com/blog/83-Configure-SSL-on-an-external-domain-name.html?category=6.html
If your registrar do not support redirects (root to www), I recommend you to use cloudflare (free) they will host your DNS and allow to create a CNAME for a root domain (they call it cname flattening)
we have a guide available here for AppDrag with Cloudflare:
https://support.appdrag.com/blog/82-Use-CloudFlare-and-activate-SSL-on-root-domain.html?category=6
