This model has a great bottom, where you can slide the magnets into place, without having to glue them.
The Fusion 360 files are parameterized, which allows you to generate every size of the bins you need, up to 7x7.
The author remixed this model.
The original used 42mm as the unit for bin heights, which should be 7mm.
I have corrected that, slightly increased the height for the magnets by 0.1mm to make them fit more easily (they still fit snug for me) and added a version that does not have the screw hole.
I have precreated the boxes in all sizes from 1x1 to 7x7 and heights 3,6,9,12,15 and 18(with and without screwhole), but you can also use the attached Fusion 360 files to generate them yourself.