It seems their email was out, but it's working again now; they responded.
I purchased the study, but it's unfortunately demonstrating some problems in displaying the FVGs on constant volume candles. But to be fair: I'm having the same problem with other fair value gap studies, though one unrelated one seems to be performing well with them at the moment (not Orderblox). I'm waiting to hear back from Orderblox on this issue; I hope it can be worked out, because the other studies they're working on look great.