Hi Pankaj,
Objective of Approval workflow is to enable Delphix Administrator to orchestrate a workflow during the masking operational. Here is how it is envisaged to work:
- Admin enables Approval workflow on an environment.

- User selects/deselects an algorithm upon a column on the inventory screen.

- User clicks submit button which is visible on "Workflow enabled" environment's inventories

- User cannot run job on the ruleset which is being changed.

- The approver Approves or Rejects the change made by user.

- User can now view approval and run the job with approved changes.

Note: Please ensure the approver or administrator has the correct privilege assigned.

Hope this helps.
Thanks
Hims