Expandable memory, often known as secondary memory, refers to any memory that can be used to expand the memory of a device. Expandable or external memory refers to a microSD card that can be removed at any moment.
Xiaomi Poco M4 Pro 5G Expandable Memory
Yes, this phone has the capability for Expandable Memory or an SD card. There is a hybrid slot on this phone, where you can use two SIM cards or one SIM card and an SD Card.