@3KillerBs and others state the requirement for 1 sq ft per bird of ventilation 24/365.Just checked - no ridge vent. Hmmm… now that would have been the bees knees. Maybe one can still be created??
Note that a ridge vent will not provide that amount so gable vents are going to be needed.
Ridge vents are standard pieces for any profile of metal roofing sheets; various types and costs. Keep digging either at big box or roofing suppliers.