Second time the ringnut breaks into pieces of the aliexpress showerhead
So I decided to try to print a replacement part

And here it is :D Hope I can help some other people with it.

For those who are interested: It's an BSPP G2 1/2 - 14 thread
(Thanks to Macki2000 for Fusion thread xml file)

I added a second version with 15mm height(instead of 16) and some grip levers for better screw on