AWS Glue giving an error: Login failed for user ''

It is recommended to try and incorporate Secrets Manager in Glue connection properties whenever possible this will help from a security of the credentials and will in some cases simplify the setup of the credentials to be used in the Connection setup.

For the issue you are facing, it looks like the connection is not setup correctly. Typically we don't use user it is username and there is typically another username like admin instead of using default database usernames like sa. Confirm that the username is correct. This is if it is a RDS database. If you did setup SA as the username, try setting up a different username and test with that instead.

Based on the error it looks like you port and URL are correct. Connection type is not in there I assume it is JDBC as well.