A statement in writing must be made, signed, and verified by the defendant, and filed with the clerk, to the following effect:
1. If for money due or to become due, it must state 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.
2. If for the purpose of securing the plaintiff against a contingent liability, it must state concisely the facts constituting such liability, and must show that the sum confessed therefor does not exceed the same.