The original part (yes, it is called “front base tube button side”) on my wife's ST2 was lost because it obviously didn't hold properly from the start and simply fell out somewhere along the road.
That's why it didn't make sense for me to buy the original part again (costs about €6!)
I quickly removed the part from my ST3, which according to the manufacturer is the same, and rebuilt it.
This model holds rock solid because it has four barbs on each side and not just two like the original.
To mount it on your bike, push it all the way in. It snaps into place with a light tap.
Just print it without support.
The model was created with FreeCAD 0.21.2
The author marked this model as their own original creation.