When a record is submitted into an approval process, it gets locked. Sometimes it’s desirable to unlock the record manually.
In Salesforce Classic, you do that via a button that shows up here:
This button is not currently available in Lightning Experience, but it’s easy to add a quick action button to a record page layout that unlocks locked records.
The quick action button will run the following Unlock Record flow, which includes two new Flow Actions: Unlock Record and Get Record Lock Status.
Get Record Lock status returns a boolean value that tells whether a provided record is locked. Unlock Record unlocks it.
Besides installing the package below, it’s very important to make sure this setting is turned on: