AP automation for controller at a low 7-figure agency?

I'm coming from corporate, I've mostly just used the bill dot com and SAP Concur at my current work.

Will be moving to consulting at an agency after the new year, first task is helping their accounting team reduce errors and work. They've got QBO set up so whatever the tool and workflow needs to integrate into it without a problem.

Additional context, agency is around 50 people, mostly younger crowd on the team so using tech shouldn't be an issue. Simple invoices, no need for PO matching, approvals are pretty standard no massive back and forth.

We don't need AI, so please no AI tools.