How Can I Anonymously Report Time Theft by Amazon Managers Working from Home?

I am aware of two Amazon managers who are committing time theft while working remotely. Both are officially working from home, but one of them has not been working from their registered home address for several months, instead working while traveling—which is explicitly against company policy.

I want to report this misconduct, but I absolutely cannot go to HR under my own name. Is there a way to report this anonymously, preferably via email? Is anyone aware of an e-mail address I can send this to? Thank you.