BG3 just has everyone use Intelligence for all scrolls - and it's very stupid.
Formally in 5e you should only be able to use a scroll if the spell it contains is on your class' spell list (wizards use wizard spell scrolls, clerics use cleric spell scrolls, etc.) - and it should use your casting ability for that class.
That is how I play it in BG3. Do not use unless it's within that character's spell list.
