How to get best in bags to upgrade an items ilvl?

I’m using best in bags because I got a new 2h Warhammer form a world quest, but it shows me as the one I have equip is much better due to I’ve upgraded it to 4/8 and its 580, but the new one is564, so says its worse, but I want to see if upgraded it would be better or worse? I’m sure this used to exist before? how do I do it because there’s no upgrade to X ilvl on the setup for best in bags?

Use the Upgrade Finder => Valorstones/Crests search. You can set an upgrade level and it will try upgrading all of your items that can be upgraded and show you a score.