After that many of the buttons on the shooting jackets at the shooting club had broken, and new one cost about 3-4 € I made this in Fusion. No fancy stuff as pattern or so, just a simple button that works as a replacement. It is intended to have a insert nut, m3 4x5 mm. Short m3 screw worked well.
Feel free to make your own version.

Printed in PLA on a Ankermake m5c, normal settings.