Print with no support and attach with M5 bolt and square nut (included in the BROR package).
This one fits on the right side. Flip in the slicer to get the mirrored version.
IKEA BROR shelving system is an excellent system to house MK3, MK4, Bambu X1C, P1P and even the Prusa XL.
The author marked this model as their own original creation.