Accessing Fitbit Data for ABCD Participants

Hey ABCD Repronim Team, I was wondering if the actigraphy ftibit data is also available on DEAP for all study participants and if not, what will be the best approach to access the fitbit data for the study participants? When I use deap to access the data (explore->main study ->novel tech->youth fitbit weekly summaries, I am seeing a lot of NAs and hence his question. My understanding was that the fitbit was given for a few weeks to all study participants.

So the Fitbit is an optional part of the ABCD Study, meaning it was offered to all study participants but they chose whether or not they wanted to opt-in. It also wasn’t introduced until the 2-Year Follow-Up, and is only a part of the even years. I imagine the NAs are just from participants who chose not to participate or it’s displaying off-years as well.