By default all walls are considered no-slip (0 Velocity at the wall). You can add extra roughness from there as indicated above. From my perspective most industrial applications do not need this setting adjusted.
As indicated in the post above, when you define material for your domain, there is an option to specify wall roughness. You can't define wall in boundary condition because any unspecified surface is no-slip wall with zero roughness by default
You can always find information, if you look in help documentation: