Even if the apps/sites itself is not fraud, but,
there are tons of scammers or fake accounts are mixing in there.
They have some typical patterns.
So, report them to ban their account,
and don't waste your time or money or feelings.
The typical characteristics of scammer account :
１：Too pretty like a TV idol.
(Such a too pretty girl doesn't need dating app basically)
２：Too sensual pic like a playmate.
（Generally, girls don't like to be seen as like a sex toy)
３：She has only a few photos.
（If she's real, she can send you more)
４：Explicit seduction messages.
（No need any explanation, right?)
５：Too fast to fall in love.
（ex: Even though she hasn't met you in person yet)
６：She cannot do video chat.
（or she does, but, quickly shut down due to bad signals
[truth is merely short counterfeit video prepared])
７：She cannot explain about her pics.
（Because, they just stole the pics for scam)
８：She is rich (pretending she's so).
（It's a trap.)
９：She can send you Counterfeit Official Documents, but,
she cannot send you "a right now selfy" with a specific pose
which you request such as 3 fingers on her ear.
１０：Mention about money or seminar or investing.
（Sometimes, she sends a URL and pushes you to click.）
And, mostly scammer try to move to LINE or WhatsApp or something
from the very beginning.
And then, mostly they disappear from the dating-app by doing unmatch right after you move to another chat appin order to prevent being reported by you as a scammer.
So, don't exchange another chat ID so quickly. If you feel the girl is possibly scammer, pretend you are not aware of it and keep some chat in the dating app until she reveals clear scammer action. You can report the scammer to ban it after you convinced.
report them to ban their account,
and don't waste your time or money or feelings!