Sorry for clickbait title.
Anyhow, if you have HP Printers and need to upgrade the firmware, you can actually download the firmware and then submit it to the printer via the “print job” form in the printer web interface to upload and update the firmware. This is easier than trying to use the “firmware sender” utility.
To do this, first locate, download and extract the printer firmware. This will be in a .rfu file format.
Next, go to the web interface of the printer and view the Information > Print tab.
Click on “Browse” under the file selector, then locate and click on the .rfu file that has been extracted.
The printer will then upload and upgrade itself. This may take a few minutes depending on size of the firmware.
Once done the printer will then tell you.