Pentax users seem to have been neglected when it comes to the world of flash. There’s been very little 3rd party support at all. Pretty much their only option, if they want TTL or High-Speed Sync is to go the Cactus route if they don’t want to go with Pentax branded speedlights. Ok, you could go with Metz, but your options become even more limited with those if you want to combine it with strobes.
It seems, though, that Godox may have listened to the cries for help from Pentax users. According to a listing on the Godox UK online store for the dual AD200 kit, Pentax TTL support is coming sometime in June. Yes, this month. Or, maybe next year.