E sim option not showing

Does your carrier support the eSim?

Check this article to find out:

Find wireless carriers and worldwide service providers that offer eSIM service - Apple Support

Any restrictions set up on your device?

eSIM support is not universal.

For example, iPhones sold in China (and associated reasons) don't support eSIM due to local restrictions

Also, eSIM is not supported by all carriers - if your carrier doesn't support eSIMs then you may not see this option.