ok, you are 2 folders too deep. Go up 2 levels to find the Firmware-1.23(3) folder in Downloads, which should be the zipped folder. then try a right click.
Alternately, you could use the Compression Folder tools at the top to extract things within the folder in your screenshot (i.e.: Downloads/Firmware-1.26(3)/Firmware-1.26 ), but I am not familiar with doing it in that way.
If you go up one folder (which you can do by clicking the arrow that points up next to the address bar TWICE, or I think by clicking Downloads in the address bar and navigating to find the compressed folder “Firmware-1.26(3)” and then right clicking [which should bring up the extract menu], though I’m not sure about that) then you should see the compressed folder.
As a side note, I usually move the compressed folder I downloaded into a “Maslow” folder so I can keep track of it in case I need to get back to a previous firmware version. When a new firmware comes out, I make an “archived firmware” folder, move the old firmware files into it and then download the new compressed folder and start again.