Esim option not available

Looks like you have an iPhone with 2 physical sim cards. Those models don't generally support eSim as they are sold in countries that don't allow eSim, such as China, Hong Kong and Macaco.

What iPhone model do you have exactly?

What is its model number in Settings ➜ General ➜ About ➜ Model Number

Where was this iPhone purchased? What country?

Also, for your safety, your screen shot will be removed, as it contains your personal phone numbers, and those should not be posted, unless you want tons of spam calls and scams.

That is an iPhone 11, 256 GB, made for sale in China, so it doesn’t support eSIM; instead it supports 2 physical SIM cards. You will need a physical nanoSIM card.

That is a model meant for sale in China. It does not support eSim by government mandate. Chinese government does not allow eSims on devices sold in their country.