Using Esim on iwatch 5 in Pakistan

iPhone Cellular Carriers that support the Apple Watch, which models, the radio frequencies each model uses, and the country where they offer service:

https://www.apple.com/watch/cellular

Pakistan is not listed.

The cellular carrier needs to support the Apple Watch because it needs to share the iPhone phone number with the Apple Watch by cloning your iPhone's SIM to your Apple Watch.

An E-sim is an electronic, or embedded, SIM. Instead of a physical card, SIM technology is built right into your phone. It’s a small chip that’s used to authenticate your identity with your carrier.So the esim is already inside your watch.Pakistan does not support apple watch cellular at this time.