How to create a block

Here it says "block menu"
https://wiki.librecad.org/index.php/Blocks
but there is no block menu
Where is it?
All I am trying to do is to create a block ))

Widgets -> Dock Widgets -> Blocks

If it is activated, an entry should appear in one of the boxes on the screen.

The wiki may be based on a older version of LC.  Also have a look at the Block List Dock under "Dock Widgets" in the Reference section and Using Blocks in the User Guide section of the LibreCAD User Manual.