Designed to fit Creality K1 keys set:  7 holes for keys up to 6mm and 1 hole for 12 mm key.

Download more boxes and holders at  https://www.printables.com/model/753388-set-of-trays-and-bottle-holders-for-multiboard-wit

This model using a modified version of the multiconnect bolt - see  original at https://www.printables.com/model/716558-multiconnect-generic-connector-for-your-board

Print it as in STL. No supports required.