Can you have more than 2 screens in your keyboard?

I find it there is not enough space in my keyboard for the font I am working on ( No Shift & Shift key pressed ). Is there any more key like Crtl key to get more screen? I might need 3 or more screens to get all the glyphs. How do you do that? Thanks

You can try AltGr (aka Right Alt) and Shift AltGr.

Thank you, let me try. Thanks