Download the latest stable firmware from the Duet Github and extract the zip file

Make sure you download the correct version. The PanelDue 5i and 7i both use the same firmware binary. The file you want is named "PanelDue-5.0i-7.0i.bin"

FYSETC documentation says to use the 5i/7i combined binary("PanelDue-5.0i-7.0i.bin") for their 5i and 7i screens. If you use the combined version for you FYSETC 5i/7i your color scheme will be incorrect.

You need to install "PanelDueFirmware-v3-7.0.zip" or "PanelDueFirmware-v3-5.0.zip"

Download and install Bossa