I can’t get my Alexa Echo Dot to play either downloaded songs or a specific playlist in my Apple Music library

First, I’d like to state for the record that I have linked my Apple Music and Alexa and made Apple Music my default music service.

So, I keep asking Alexa to either play downloaded Pop songs in my Apple Music library or play one of my Apple Music playlists, but it either just plays a radio station or tells me that I need a connected accessory.

How do I fix that?