[Neru]

Stock app. That's about it. There's some apps with optimised settings like One Note but drawing with them is not fun- in some cases you can't even see the thickness of lines changing until the screen refreshes. All the other apps like Krita, Medibang paint, Clip studio, etc- they all lag. I can assume you already tried those? Unless you are okay with current app, then its all good. It can be done but not very fun, at least for me.
I would instead suggest getting a Samsung galaxy tablet or some of ipads. I'm using Tab s4 for drawing, its way more fun to draw than with Boox and second hand ones even in perfect condition are even cheaper than ipads. Not only that, Samsung tablets also support the same pens that Boox does- so I use the same Wacom One pen for note taking and reading/ referencing from anatomy books on Boox and drawing on s4.