[MM3-users] How do I specify the TCP port number for Postgresql?

The mailman.cfg file on the system I am working on includes this line:

url: postgres://mailman3:mailman3:@localhost/mailman3

This works fine as long as the postgresql server is at the default port number of 5432. How do I specify a different TCP port number? My guess is that a change to this line is needed, but unfortunately, it is not obvious to me how to make that change, and I have been unable to find this information in the mailman3 documentation or in a previous mailing list post. Feel free to point me at the documentation or post that I have overlooked.

Thanks,

Ken