Keep my free Google Apps with a custom domain while using the same domain with Proton Mail

Goal: maintain free Google Apps and move shaunluttin.com email to Proton Mail.

Proton Mail Steps:

1. Log in at protonmail.com
2. Click Settings | Domains | Add Address
3. Follow the required set up steps.

Those steps might take several days and require making changes to the Google Apps/Suite DNS settings.

Google Apps/Suite DNS Settings:

1. Login at admin.google.com then follow this click path:
2. Domains
3. Add/Remove Domains
4. Advanced DNS Settings (note the username/password)
5. Sign in to DNS Console (with that username/password)
6. Gear > Manage DNS

That will open the Google Apps DNS management page, where we can add/edit the DNS settings necessary for moving from Gmail to Proton Mail.