You can write the inversions (slash chords) and see them the in diagrams, and a musician can interpret this as required, however the player itself does not specifically play them (other than the bass instrument playing the bass note of the inversion).
For example, if you want the piano sound to play second inversion of Dmaj, it will not necessarily play A, D F# (bottom to top) as a voicing. It will just see Dmaj and randomly play a Dmaj voicing. (Each time the play button is pressed, the notes, voicings generated are randomly chosen, so although you might have your inversion correctly played, it may not happen each time you play the song.)
For very specific playing, it would be better to use a DAW, midi, sequencing etc. (Some users export the midi file of the song for further editing, using iReal Pro as a starting point.)