I just downloaded a song from iTunes on my iPhone 12. How do I set as ringtone?

Good day Glesga86,

The following articles go over where to purchase Tones from, as they aren't full songs; they're just snippets. They are purchased from a different area on your device. 

• Get ringtones, text tones, and alert tones in the iTunes Store on iPhone
• Use tones and ringtones with your iPhone or iPad

Buy ringtones from the iTunes Store

1. Open the iTunes Store app.

2. Tap More.

3. Tap Tones. 

4. Find a ringtone that you want to buy, then tap the price.

5. Choose an option to automatically set the ringtone. Or tap Done to decide later.

6. You might need to enter your Apple ID password to complete your purchase.

Thanks.