Hi there! My name is***** am a computer professional with over 15 years of experience with both Mac and Windows computers, phones, tablets, and printers. It would be my pleasure to assist you with this.
One of the reasons that Macs are so secure and get a lot fewer viruses than Windows computers is that you have to have the Administrator password ***** order to make any changes to the operating system, such as updating printer drivers or installing new programs. The Administator password ***** not be the same as you Apple Account password.
Luckily you can reset it if you have forgotten it. Follow the steps below to reset the password:
Now you should be able to install the firmware. Please give it a try and let me know the results.