iPod 5th Gen stuck connecting to MacBook Pro

Elderly Apple 5th Gen iPod, still works perfectly (well done Apple), but I don't know if I can access/manage it from my new MacBook Pro (or am I doing something wrong)

Plugged in, MacBook recognises it, asked if I wanted it to connect, but I've had the "do not disconnect" message plus the flashing No Entry sign on the iPod for ages it seems.

I'd hoped I could manage the music on it but don't know if I've done everything correctly.

Any pointer would be appreciated.