The instinct when a fake or unfair review shows up is to respond immediately and forcefully. That instinct is usually wrong, and it's worth knowing why before you type anything.
A public reply is permanent and visible to every future customer who reads that review, not just the person who wrote it. An angry or defensive reply, even when you're completely right about the review being fake, tends to read badly to someone with no context. It can make a fake review look more credible, not less, because now there's visible conflict instead of just an unverified complaint.
What actually helps: a short, calm, factual reply that doesn't argue the specifics publicly. Something like acknowledging you take the feedback seriously and inviting the reviewer to contact you directly, whether or not you believe the review is genuine. This does two things: it shows future readers you handle feedback professionally, and it doesn't hand the reviewer more material to escalate with.
The flagging or reporting process, separately, is where you actually make the case that a review violates a platform's policy. That happens through the platform's own reporting tools, not through your public reply. Keep the two separate: respond calmly in public, document and report through the correct private channel.
Dealing with a review right now:
We handle the documentation and reporting side so you can focus on a calm, professional public response, without the two getting mixed together.