From the section to copy another use is to use
sequel -C mysql://host1/database postgres://host2/database2
Is there a way to include username and password for both databases. Tried with no luck
sequel -C mysql://user:password@host1/database postgres://user2:password2@host2/database2
The usernames and passwords are stored in the user database. You first need to setup a user on your target database. Before that you can't copy anything to it. Copying the user database from mysql to postgres is not going to work either imho so you will have to setup your user manually first.