simply do a right click on the website you wish to see the source code and the option is near the bottom of the menu

You can find View Page Source in the Web Developer sub menu.

• Firefox > Web Developer > Page Source
• Tools > Web Developer > Page Source (Cmd/Ctrl+U)
• Right-click on a web page to open the right-click context menu and select Page Source

Thanks for trying to help - but when I do this nothing appears to happen. However when I go to the Fifefox icon on the task bar I can see, in effect, a thumbnail of the source page - but I cannot get it "up" to actually see!

So I am still stuck

I found it helpful... on the page of the site itself, right-click mouse if you have a PC (or a mouse capable of this), or press the Control key down and click the mouse on a MAC

I've tried all of this several times and it doesn't work.

command U