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
Lenovo Legion 7i - Upgrading the Storage - YouTube
Amazon.com: Lenovo Legion 5 15.6" Full HD IPS 165Hz Gaming Laptop (8-Core Ryzen 7-5800H, 32GB RAM, 1TB PCIe SSD, GeForce RTX 3050 Ti 4GB) RGB Backlit, 3D Nahimic Audio, w/HMDI Cable, Windows
How to upgrade the SSD in your Lenovo Legion Y7000 | Windows Central
Lenovo Legion 5 15 inch - DIY adding an internal SSD - YouTube