When your brother printer is not working on the windows 10 pc, and it keeps showing you the incorrect username or password. It means, something is wrong with the printer.

• Disconnect the printer and then reconnect it to the network.
• Update the printer on your computer.
• Uninstall the printer and then install  the printer again.

once you will make these changes into the brother printer. you need to visit: how to get printer online brother