The original Fairphone USB-C to Mini Audio Jack Adapter works perfectly! You can change the volume as you like and play and stop also work. 
Maybe it doesn’t work with every headphone? I don’t know. I tested it with this one:
The original Fairphone USB-C to Mini Audio Jack Adapter works perfectly! You can change the volume as you like and play and stop also work.
Maybe it doesn’t work with every headphone? I don’t know. I tested it with this one: