Plain square brushes

Where can I find plain square brushes?  I have been all over the brush tool settings - I can only find artistic brushes that have ragged edges. 
How have looked online where people say that Photoshop comes with them, but I don't have a selection that says square round brushes in the drop-down menu.  Round and artistic I have, but if there are square brushes, I am not seeing them. 
I am using a Windows10 machine, cc, build 21.2.4.  My skill level is advanced beginner, so if this sounds foolish, I apologize.

Any and all help is appreciated.