These labels are hardcoded in the Identity Portal
Identity Portal 14.1, 14.2, and 14.3
The label that appears on the approval workflow timeline in Identity Portal uses the same word as the corresponding action button. So if the user clicked on "Approve", the label that will appear later in the timeline will be "Approve" as well. It works the same way with other languages. It is not configurable. You can change the localization of the button and it will also affect the label the will be displayed later in the timeline, but it will always be the same word for both the button and the label. This is by design. Changing that behavior is an enhancement request.
To open an idea/enhancement request use the link below: