https://domains.google/#/

• install google appengine
  • configure environment PATH variables
• google cloud developer console
  • create a project
  • get the project ID
• set your go version in the app.yaml file

runtime: go113
handlers:
- url: /.*
  script: auto
  secure: always

• deploy to that project. update --project with your project-id

gcloud app deploy app.yaml --project=<YOUR_PROJECT_ID>  -v 1
my example:
gcloud app deploy --project temp-137512

• view your project
  • https://YOUR_PROJECT_ID.appspot.com/

example https://temp-145415.appspot.com/

change DNS info at google domains point your domain to your appengine project