A ProcessError occurred. -Permissions related error for Ghost start

:heavy_multiplication_x: Starting Ghost
A ProcessError occurred.
Message: EACCES: permission denied, open ‘/var/www/ghost/config.production.json’
Exit code: EACCES
Debug Information:
OS: Debian GNU/Linux, v10
Node Version: v14.19.0
Ghost Version: 4.34.2
Ghost-CLI Version: 1.18.1
Environment: production
Command: ‘ghost restart’
Additional log info available in: /home/root_proctr_me/.ghost/logs/ghost-cli-debug-2022-02-01T21_57
Try running ghost doctor to check your system for known issues.
You can always refer to Ghost-CLI - A fully loaded tool for installation and configuration for troubleshooting.

What are the correct permissions?

The instance is running on Google Cloud.