According to Fiverr TOS, it is a violation to contact with buyer outside Fiverr’s own messaging system. I know this has been done for the safeguard of buyer as well as sellers. But sometimes there needs to be long discussions with the buyer which can’t be done through Fiverr’s messaging system.
I think Fiverr should introduce a video messaging system itself or officially partner with online meeting platforms like zoom so that buyers and sellers can have long discussions.
Personally I think those buyers who try to lure sellers to contact them outside fiverr are scammers. Fiverr system should ban those buyers.