I am curious if anyone knows how to accurately sex Turner's Thick-toed geckos (Pachydactylus turneri) (AKA and sold as "Bibrons" or White-spotted Wall Geckos (Tarentola annularis)

I have been told neither has sexable via bulges and or pores, (do they even have visable preanal pores like other geckos ?) and had other people tell me they were....(if that the case all mine are females)

Any advice/experience with either of these species would be appreciated - Thanks -