So I have some panel data, investment in different regions over the course of a 7 years. It's non stationary, and I'm hoping to use it in a Pooled OLS, as my dependant and other independent variables are all stationary.

Here is a Levin Lin Chu result : https://i.imgur.com/eAmB9v6.png

Here is a scatter of the data : https://i.imgur.com/5r4lS87.png

It's currently in real terms, not nominal, but there is still a deterministic upward trend. Is it valid to just log the data and use that variable? Or would it be more statistically sound to detrend it? Does anyone have any book or paper recommendations to guide me, because I'm pretty confused.