A draft is waiting when you open the review
When a new Google review arrives without a reply, RepBot queues a draft for it. Each draft lands in Approve Reviews, marked Pending Approval, beside the review it answers. Star-only Google ratings get a draft too, matched to the rating, and so do reviews you add by hand.
Drafts follow the Brand Rules you set for each Profile. Reviews start arriving the moment you connect, so your inbox is already full when your rules go live.