Embedded SIM, or eSIM, is a SIM card that may be programmed into a phone, and no need to insert it manually. It acts similarly to a traditional SIM card, but it does not require a physical card and can only be used on devices that have pre-installed eSIM compatibility.
Xiaomi Poco M4 Pro 5G is a mid-range that cannot support eSIM. There is no eSIM capable function pre-install on this device. It is a hybrid-SIM smartphone.