I bought my 13 iPhone from Dubai it has a dual sim. Does it support eSIM

Using Dual SIM with an eSIM --> Using Dual SIM with an eSIM - Apple Support

An eSIM is a digital SIM that allows you to activate a cellular plan from your carrier without having to use a physical nano-SIM. With iPhone 13 Pro Max, iPhone 13 Pro, iPhone 13, and iPhone 13 mini, you can use Dual SIM with either two active eSIMs or a nano-SIM and an eSIM. iPhone 12 models, iPhone 11 models, iPhone XS, iPhone XS Max, and iPhone XR, feature Dual SIM with a nano-SIM and an eSIM.1

eSIM on iPhone is not offered in China mainland. In Hong Kong and Macao, iPhone 13 mini, iPhone 12 mini, iPhone SE (2nd generation), and iPhone XS feature eSIM. Learn about using Dual SIM with two nano-SIM cards in China mainland, Hong Kong, and Macao.

Yes. You purchased a grey-market iPhone in Dubai, as the dual-SIM model is not sold in Dubai.