Yes, Legion 5 Pro has two NVMe PCIe 3.0 2280 SSD slots, the second slot is empty and has a pre-installed heatsink with a thermal pad. (I installed Samsung 970 Evo 1TB
How to upgrade the HDD in your Lenovo Legion Y740 | Windows Central
New original Laptop SSD SATA Hard Drive Cable HDD Connector For Lenovo Legion Y7000 Y7000P Y530 Y530-15 5C10S29929 NBX0003YN00
Under the Hood of the Lenovo Legion 5 & SSD Tests - element14 Community