How do I add a media image field? I have installed these modules:


Media Entity 
Media Entity Image 
Entity Browser


When I try to add an image field, I have no widget for Media like there was in Drupal 7.
I also tried to add a reference to a media, but it doesn't seem to work.

What am I doing wrong?
What you got can do what you want, but it requires configuration and without a UI it's quite hard.

You might want to try adding the file browser module, which uses Dropszonejs to create a nice file browser widget. I have tested it out and it seemed to work just fine, but it wasn't quite mature enough for what we wanted to do at the time.