From Shantinath Patil: Pre-filling values on the Appointment Review Screen
So you want to preload some values on the final Review screen provided by Scheduler?
Check this out…
Let’s say you want to prefill the email & phone details.
- Set the Email and Phone in the first assignment stage:

2. Assign Service Appointment record variable in the review screen. In an Outbound flow template that input is blank and that’s why making changes only mentioned in step 1 will not work.

That’s it!

Note this method works for the Outbound flow & Inbound flow and is restricted to the following fields:
- “AdditionalInformation”
- “AppointmentType”
- “Comments”
- “ParentRecordId”
- “ServiceTerritoryId”
- “Street”
- “City”
- “State”
- “Country”
- “PostalCode”
- “SchedStartTime”
- “SchedEndTime”
- “WorkTypeId”
- “Id”
- “Description”
- “Subject”
- “Phone”
- “Email”
- “ContactId”
- “IsAnonymousBooking”
To prefill other fields or for other flows (eg Guest Flow), you need to do it build your own screen & logic: https://unofficialsf.com/build-your-own-appointment-review-screen/
Also check out other cool changes that you could with the review screen here: Review Appointment screen: Quick Flow Customisations – Salesforce Scheduler