Notify with on-call scheduling requirements Certain configuration steps are required to use Notify with On-call scheduling. You must add at least one Notify phone number to the On-Call Group number group. This group is configured by default to handle inbound SMS responses that accept or reject an on-call assignment. You must configure any outbound SMS workflows, such as the On-Call: Assign by Acknowledgement workflow to use this Notify phone number to send SMS messages. Edit all Send SMS activities in these workflows to use this number as the From value.