Laser engraving and cutting platform clamping to support platform

The manual does not show parts that need to be attached to Laser engraving platform to clamp to support platform. What are the parts called and where are they. When I look at pictures in manual it shows screws through holes but there is no explanation on this. There is nothing under my laser platform for it to clamp to

This ist the place

This is not what I was asking about. The actual platform clamping to the under support is the missing piece. There is no piece on the underside of laser platform at the front to clamp it to the under support

I’m sorry for the late reply.
If you mean this part. That was pre-assembled on the laser platform for me.
If you don’t have it, that’s a case for support.