In Sql server management studio, make sure for a server name you use the unraid server name or IP address. You can also append ,1433 on the end of the server name to give it an extra hint to use TCP/IP to connect. For example, connecting to an ip of 192.168.0.200 you would specify: 192.168.0.200,1433
you also need to select SQL server authentication from the authentication dropdown (so that the username/password boxes become writable)
username is: sa
password is: <whatever you configured on the docker config page>