Unable to see iCloud Music Library option in Music Settings
Whatever device it is that you don't have the "iCloud Music Library" option available to click on is logged into a different apple ID. I had this problem getting apple music on my Mac, I had signed up on my iphone. if it does work on one device, check in the settings and see what it says is the apple ID linked to the apple music account. I had been logged in under an old ID on my Mac's Itunes. I signed out and signed back in with my more recent ID from my phone and apple music turned on automatically, and the "iCloud Music Library" appeared in my preferences menu. Hope this helps