iReal Pro does not include melodies or lyrics. Copyright and licensing with the publishers prevent it, so a chart holds the chords, the form, and the backing track, but not the tune or the words.

 

If you need them in front of you, keep the melody or lyrics in a separate PDF or notation app (forScore, MobileSheets, and similar apps) and run it beside iReal Pro in split screen on an iPad or Android tablet; iReal Pro keeps playing in the background. You can also add your own text to a chart with the Editor's text tool.

 

For more, see Edit a song on the iReal Pro website.