Were they not using some kind of third party identity verification service? That's what I usually see apps do. Don't tell me those third party services still share your ID with the app (like the actual images)?
Read the article. They clearly have their own OTP setup.
But if they are asking for your passport, then they have access to it. It's not a third party asking and providing them with some checkmark or other reduced risk data.
I have read the article and OTP has nothing to do with identity verification. I'm asking because every single time I went through identity verification the app used a third party service that is supposed to be trustworthy.
