Force folder size

apologies in advance, i'm sure this is out there somewhere i did poke around a bit first...
how do i force the size column to display the size of folders (incl subfolders)
trying to use the bar graph display of relative size

Please link your account first, as requested many times now.

sorry about that, kind of new to this, done now

Many thanks!

Calculate Folder Sizes Automatically has information on configuring Opus to look in folder contents and populate the size columns for folders, either for all folders or just certain locations.