Yes, the exact terminology in the constitution is that the president must be a "natural born citizen". There's debate on the "natural born" part. For example, Ted Cruz was born Canadian, but his mom was from the US, which conferred him US citizenship at birth as well, so he's debatably "natural born". John McCain was born in the Panama canal zone, which was a US territory at the time (and his parents were citizens), but there still was some debate at the time.

Zohran is basically just a regular immigrant who became a citizen, with no way you could claim the "natural born" part.

What makes it so impressive is that he can do this on the fly. Incredibly quick. Really one of a kind.