Here Xhorsevvdi shares the
There should be a screw fixing the key on different positions.
How to Install M3 Fixture?
Adjust the screw to insert key in/ out.
1.Loosening the screw by turning it counter-clockwise
2.Install M3 clamp to the holder and push it to the limit of left
3.After the clamp is put in the clamp platform, tighten the screw
Hope this could help!