How to upgrade the SSD in Lenovo's Legion Slim 5 14 (2023)
SSD Upgrade for Lenovo Legion 5 15ACH6H 512GB/1TB/2TB | eBay
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