Ghost won't start after changing the host variable in config.production.json

I have a AWS ec2 instance ubuntu, where i installed ghost, earlier it was only opeining in localhost only, so i changed the host variable in config.production.json from 127.0.0.1 to 3.83.106.26 (my instance’s ipv6 adress)

But now when i start it with ghost start i get this error “config file is not valid JSON

Earlier my config.production.json file was this, and i have just changed host variable at line 4