I had to use a solder iron to heat up a 10 cents US coin to insert to the slot. There's no easy way to put coin in from my experience. You can try print it side way with support but I just don't know how to insert coin half way print without interfere with support material that was automatically generated in the slot.
Edit: after few tries, this has to be printed side ways for the bottle opener to work properly.
The author remixed this model.
So I added the bottle opener at the other side of the cabinet opener to replicate the original Siemens cabinet opener which literally is a bottle opener. I also put another original version without the bottle opener.