Start a new document with the shape you want to convert, I used my website's logo . It consists of three paths.

Use text tool to write the words you want to fill your shape with. I wrote "Darkion" .

Select your shape's layer and the text you wrote, then from "Text" menu , use "Attach In Path" option.

After repeating the steps for three times (since my shape consists of three paths) , it should look like this.