Hi,
Form the screenshot it looks like that pgAdmin4 is not able to connect to database server.
It's hard to say anything with the information you have provided, Could you please provide more information about your environment?
- How did you install pgAdmin4?
- Is `localhost` mapped to IPv4 or IPv6?
- Where is your DB server running, Is it on `localhost` OR in Docker?
- Are you trying to access your local DB server from pgAdmin which is running under Docker?