Everything you can build with OOP can be done with FP and vice-versa. So the question is which one's strengths you'll most benefit from.
OOP's strengths surround modeling nested object structures and encapsulating state and logic within opaque containers. If you're primarily writing data to/reading data from a relational database, everything gets flattened and exposed. So you have to ask yourself what you're getting from it at that point.
Rendering and processing are well-suited to FP. "Email sending" and "notifications" are vague, but I see nothing about SQL + FP that makes those harder.
Business objects need a lot more, from rendering, processing, email sending, notifications, etc.
All those things are well approximated by an object and poorly approximated by SQL.