This is not configurable from Firefox. You can check the keyboard options for such a setting.

Thanks! it is exchanged in the variable "inputtype" which changes based on mouse down in various types of form fields ie the URL window. They dont even make a keyboard app that can control that on Android OS. I thought perhaps I cohld specify inputype in aboit congig for that URL window. It should be text.. no need fir a ,com buttonnit rearranges the entire lower row and shrinks the spacebar to half its size.