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 5 Upgrade SSD: Get Stepwise Guide Here
I'm trying to install a 2nd ssd on my lenovo legion 5 : r/LenovoLegion