This question has not been answered and I cannot find any information online either. For example, I have installed the beautify extension to format my code. HOW DO I RUN IT? I have tried the following all of which do nothing:
Select all,, open the Command Palette (Ctrl-Shift-P) search for and click on the extension.
Select all, open the Extension Palette (Ctrl-Shift-X) click on the extension.
Assign a key command to the extension, select all and use the key command.
Even if I don't select all nothing happens. Extensions are useless if you can't run them.