How to set a ringtone from a purchased song

I purchased a song using my Apple ID so that I could use it for my ringtone on Iphone 14. I see the song in the Music App and in the Itunes App. I selected to download it and it says downloaded but it is not showing up on my downloads on the Itunes App. I want to use the song purchased as my ringtone. It is not showing up under settings and sounds as downloaded tones. What do I do now?