Please have a look at the certbot-dns-google documentation first.

Procedure :

• Edit domains in the compose file
• Edit Google credentials in google.json file (generate using https://developers.google.com/identity/protocols/oauth2/service-account#creatinganaccount)
• Run certbot only and wait for certificates to be generated : docker-compose up -d mycertbot
• When certificates are generated, run your services : docker-compose up -d