Where do I machine the doors for the flush bolt on my Room Fold folding sliding internal doors?

Where do I machine the doors for the flush bolt on my Room Fold folding sliding internal doors?

Room Fold doors are not pre-machined for the flush bolts.  We recommend flush bolts are placed at the top of the door to connect into the frame head. Fitting instructions supplied with the doors will provide full guidance for where to position the flush bolts for each specific door configuration.