Request song to apple music

I don't recall seeing any specific place to request music. I would contact tech support/Customer service. Everything on social media has to do with music licenses. Sometimes they expire if there isn't enough demand for it. But, if that's the case, there is no reason why iTunes can't request or renew the license on the music you want here.

Not if it’s a small independent (no label) you’re referring to. It costs money and lots of hard work to get your music up on the streaming sights unfortunately.

You could ask the publishers as they're the ones that distribute it.

That's true too. Everything costs lots of money. Even twitter/facebook ads. Can be very discouraging.