Hi JJ, sadly, in Firefox, the Options menu voice is not part of the menu that comes out when you right-click over the extension icon! :(

You have to right click the icon, select "Manage extension", then click over the three dots in the upper right part of the page (next to the switch that allows to turn on/off the extension) and then click "Options". Once you do all of these steps, Options page will spawn again. :D

That's a bit overcomplicated, indeed... instead in Chrome/Edge, the Options menu voice is already part of the extension icon's right-click menu, so things are a lot easier there.

Maybe I could try to make the options page come out as user clicks or double clicks over the icon extension in FF... I don't know even it this is possible, I'll investigate about that! ;)
Thanks for your suggestion and your precious review!