How to access the internet using eSIM card on iOS devices?

Install the eSIM or insert the physical SIM card.

Go to [Settings] - [Cellular], select the corresponding card and enable [Data Roaming].

Confirm [Cellular Data] is enabled and the APN is set to automatic.

If unable to access, toggle airplane mode for 30 seconds and turn it off, or check if "Low Data Mode" is enabled and disable it if necessary.