A statement in writing must be made and signed by the defendant and verified by his oath to the following effect, and filed with the clerk:
A. if for money due, or to become due, it must state fully and concisely the facts out of which the indebtedness arose, and that the sum confessed therefor is justly due, or to become due, as the case may be;
B. if for the purpose of securing the plaintiff against a contingent liability, it must state fully but concisely the facts constituting such liability, and must show that the sum confessed therefor does not exceed the same.