Setting up Blogger with Google Domains should be a real piece of cake considering that both products are owned by the same company. WRONG!
As of Oct 2019 the Blogger documentation doesn’t match the UI and therefore missing options for allowing an integration that should be an out of the box experience.
Here is what you have to do in order to make your own Google Domain host to work with Blogger.
Login in Google Domains, enter the management of that domain and add the following records to your Custom resource records.
If some already exist, leave them alone.
1 & 2 are basically confirming to Blogger that you are actually the owner of the domain. A safety check. You will find that information to enter in those records in Blogger at the time you set to configure your custom domain.
3 & 4 instead guarantee that if someone types www.yourdomainhere.com the name gets resolved.
Google Domains doesn’t support root domain which means if you leave everything as is, your domain will not be resolved if a user doesn’t type the www in front of the domain.
To solve this other problem (thank you bigG) head under Synthetic records and set a subdomain forward. I know… it seems awkward and it is but don’t let the nomenclature fool you.
In the subdomain text box enter @ and in the destination url enter you will domain www.youdomain.com like shown below.
You are welcome.