Welcome to Apple Support Communities.
It's my understanding that you're unable to locate the feature to share music with your friends. I may be able to help you with this. Here's a great article to start with: See what friends are listening to in Apple Music
Make sure that you're up-to-date: Update your iPhone, iPad, or iPod touch
Also, check the restrictions settings. Either turn off restrictions or make sure Music Profile is turned on. Go to Settings > General > Restrictions > Music Profiles & Posts, this should be turned on.
Let me know if this helps.
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