I had the same problem. It works so easy in M100. But here’s what you do in FCP:
1. Double click your track with graffiti
2. select the “controls tab”
3. from the FCP timeline drag the clip that you want Graffiti to reference and drop it on one of the little windows (marked video 1-6) with a “film reel’ and question mark in it in the controls tab.
4. double click the “boris graffiti logo.
5. Graffiti launches
6. Add a “background track in Graffiti (1st box/upper right V1)
7 In the new background track it should say “V1” select it and in the drop down menu select the track that you put your clip into from FCP (I usually use V2).
8. Voila! you should now see you background track in Graffiti.
9. When done laying out your text in Graffiti, delet the background track and hit apply to return to FCP.
Hope that helps and is clear.
Happy editing!
Kevin