How to scroll an element to the end?

Question

Python

There is the following code:

def scroll_to_down(self):
        print("Скролим вниз")
        lastHeight = self.driver.execute_script("return document.body.scrollHeight")
        while True:
            self.driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
            sleep(3)
            newHeight = self.driver.execute_script("return document.body.scrollHeight")
            if newHeight == lastHeight:
                break

however, the problem is that on the page you need to rotate not document.body, but document.body.div (class app), how can you specify this in js ? Or maybe you have another example of how to implement this ?