iReal Pro exports a song two ways, each for a different job.
 
MIDI (Export → Audio MIDI) captures the notes and chords each instrument plays as iReal Pro performs the song. Open it in a DAW like Logic or Cubase.
 
MusicXML (Export → Chord Chart → MusicXML) captures the chart itself, the chord symbols and the form. Open it in notation software like Sibelius, Dorico, or MuseScore.
 
For the full walkthrough with examples, see Export to MIDI and MusicXML on the iReal Pro website.