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 or add an SSD to Lenovo's Legion 5i 15 | Windows Central
Lenovo-Legion-5-15ARH05H-max-capacity-NVME-SSD - English Community - LENOVO COMMUNITY