We use
Bill.com and I've been meaning to create a new custom role to try to get away from the admin for integration - it's disappointing to me that that's the only way they tell you to set it up rather than having a list of required permissions. I haven't done it yet so I can't say if it'll work or if there's something it's doing that actually needs admin-level access. If someone else has tried this though, I'd love to know if it works.