You turn the words into audio, keep it to about 30 seconds, and set the file as your ringtone. The simplest route is a text-to-speech tool, which reads the text aloud. It works, but it sounds like an announcement.
Text-to-Ringtone is the newer route: an app writes music around your words and sings them. That is what Ringoz does. You type a name and a line of up to 100 characters, pick a style, and get an original sung ringtone, mastered to loop cleanly. Then set it the usual way: in Settings on iPhone, or in Sound settings on Android.
Related questions
Can AI make a ringtone for me?
Yes. AI apps can now write and sing an original ringtone from a few words.
How can I make a ringtone with my name in it?
Record or generate audio that says your name, or use an app that sings it.
How do I make a custom ringtone on iPhone?
Get a sound of 30 seconds or less, add it as a ringtone, then pick it in Settings.