Provided the automated email/text message has not been sent to the candidate, on the candidate's timeline hover over the scheduled automation and click the trashcan icon. This will cancel the automated email/text message and the cancellation will be noted on the timeline.
Important: Your hiring role will need to be Hiring Manager and above to perform this action. It's not required to be the sender of an automation to cancel it.
Alternatively, you can move the candidate out of the stage where the automation will occur. An automation can only run if a candidate is in the relevant stage. The automation will be attempted again if the candidate is moved back into the stage. Automations will not be attempted again if they have already been completed for the candidate (i.e. the candidate will never receive duplicate automated messages).
Automations that are set to run "immediately" won't provide time to allow canceling. We recommend setting a short delay for all automations in case you need to cancel.