How to Insert media with command-M on a mac?

[Johannes Schneider]

command M makes the window move to the dock. 

control M does not work on my confluence page. 

So how can I insert media on my confluence page with a shortcut on a mac (10.13.6 (17G65)) using safari Version 11.1.2 (13605.3.8)? 

thx, Jo

[Jack Brickey]

Duplicate post.