No option to purchase a song on iTunes (on a PC or iPhone)

I recently tried to purchase a song using both iTunes on my laptop and the Music app on my iPhone (phone and app are both up to date). In the Music app, my only option is to purchase a Music subscription, which I don't want to do. In iTunes on my laptop, the only options are: gift this song, add to wish list, tell a friend, share on Twitter, share on Facebook, and copy link. What happened to the purchase option? I found another thread from January of this year on the same issue, but the solution wasn't in the thread and I couldn't send a reply to anyone who commented on it.