eSIM Feature not available on iPhone 13 Pro Max

I bought an iPhone 13 Pro Max Dual SIM in a local shop. When I look under Mobile settings, I cannot see eSIM. I have searched the internet to find out the reason, but cannot seem to find any answers. Is there anyone having or who has had same issue and found a solution?

Details of the phone & OS Version:

iOS Verson: 16.5.1 (c)

Model Name: iPhone 13 Pro Max

Model Number: MLH93ZA/A

Serial Number: (I am not including this now, unless an Apple Support person requests).

SIM Tray: Dual SIM

Any help, tips or response will be appreciated.