How do I buy iTunes music on my Android phone?

Thanks for your advice, but I tried the three-month Apple Music trial and discovered I couldn't purchase music through the Android app. Neither can I purchase it through my iTunes software since that version on my MacBook is no longer supported by Apple. And it has the latest possible MacOS software I could install. Since I don't want to pay the monthly Apple Music fee nor switch to an iPhone, there's nothing more I can do through Apple's music service.