How to delete Lightroom local storage on iphone?

Hi guys,
My iphone's local storage on the verge of exploding, and I realized that the lightroom local storage is occupying a lot of GBs.
I browsed on the web on methods to reduce storage (like clearing the cache) but it doesn't help with the local storage of lightroom on the phone. I saw a post saying there is a method to 'disable store locally' so these photos get moved to the cache and I can clear them. Does anyone knows where is that button?
thankss

