passbolt.local is a dummy hostname that doesn’t exist on the internet and it is for test purposes only. If you want to continue using it you should add an entry on your /etc/hosts like the following:
ip_of_your_container passbolt.local
If you are running docker from linux ip_of_your_container would be the ip address of your running passbolt container (you can obtain it using docker inspect container_id). If you are running macos or windows, most likely ip_of_your_container would be 127.0.0.1