ProShot 3.7 app

[AC Question]

I downloaded ProShot 3.7 but developer is not responding so I want to ask here. I set to save photos to external SD card - it works, but if I want to see preview (swipe right) there is still default camera folder in the internal storage (but it doesn´t work even if I set up photos to save in another folder in the phone). Also it says it can´t write to SD card when I´m trying to make a video (but photos work). All permissions set.

Phone is LG Flex 2 with Android 6. Thanks for the reply