given you have a div element you need to scroll inside, try this piece of code
document.querySelector('div').scroll(x,y)
this works with me inside a div with a scroll, this should work with you in case you pointed the mouse over this element and then tried to scroll down or up. If it manually works, it should work too
Update
This is a better way to handle the scroll
scrollTo(0, document.body.scrollHeight)