If you’ve already created an automated action, you can add it to your approval process.
|Available in: both Salesforce Classic and Lightning Experience|
|Available in: Enterprise, Performance, Unlimited, and Developer Editions|
|To select approval actions:||“Customize Application”|
Open the approval process that you want to add an action to.
From the appropriate related list, click Add Existing. If that button is hidden, click Show Actions.
Choose the type of action.
Move the action from Available Actions to Selected Actions.
Save your changes.