On appeal, what is the effect of a finding that a motion to amend or amend the complaint is futile?

On appeal, Plaintiffs do not explicitly argue that the bankruptcy court should have given them an opportunity to amend their complaint or that it erred in finding amendment would be futile. In fact, they never asked the bankruptcy court for leave to amend, nor did they propose any new allegations that would cure the plausibility issue identified by the bankruptcy court. Plaintiffs have thus waived the issue. Smith v. Marsh, 194 F.3d 1045, 1052 (9th Cir. 1999). In any event, we see no error in the bankruptcy court's conclusion that the deficiencies of the complaint could not be cured by any amendment.