Two steps: Start Gmail Receipt Scan to begin, then Get Gmail Scan Status after a Delay to find out what happened. Same start-delay-poll shape as a receipt upload.
Before it will work
Gmail must already be connected inside ExpenseBot. The action uses the Gmail access you authorized in ExpenseBot; it does not grant that access itself and it cannot scan an account ExpenseBot has never seen. If you have several authorized accounts, map the address into Connected Gmail Account to pick one.
Setting the range
Either map Lookback Days — the number of recent days to scan — or map Start Date and End Date together. Do not mix the two. The range is inclusive and the end must fall on or after the start. Subscription limits on scan depth still apply.
The action requires a Source Event ID like every data-creating action, so a retried Zap does not launch a second scan.
Reading the status
Get Gmail Scan Status returns the current or last scan. Repeat it after a Delay until the scan is no longer in progress, then read the counts: receipts added, duplicates, skipped, errors, and an Action Needed Count.
Route a non-zero Action Needed Count to the Action Needed URL the step returns, and send that link to whoever owns the books. A scan that finished is not the same as a scan that was clean — assuming it was is how receipts sit unreviewed for a month.
A useful pattern
A Zapier Schedule trigger → Start Gmail Receipt Scan → Delay → Get Gmail Scan Status → Filter on Action Needed Count greater than zero → notify. That gives you a scheduled scan that only interrupts a person when a person is actually needed.