The eSIM option does not appear on my iPhone

If you're in China, nothing. Otherwise, use only physical SIM cards, or buy one intended for your country; aside from the eSIM issue, you'll likely be denied warranty or AppleCare+ coverage on it.

(249874)

That unit was originally sold in China; it's banned there.

(249872)

What is the model number found at: Settings - General - About = ???