Minecraft creeper knob

Requires 1 x M3 screw. Length will depend on the depth of your closet doors / tray panel. 

There are 2 variants: one for a square M3 nut, and one for a M3x4x5 threaded insert

There are 2 sizes: a shorter and a longer one

The ones in the picture are printed in TPU 95A. If you are planning on using a similar material (flexi) I strongly suggest the nut variant because the threaded insert won't grip well with the material