Choose 'Reviewers' and add people who will be able to change some fields before the approval:
Save your changes.
Now, approvers who also were added to "Review and coding matrix" can change Bills according to the defined rules.
Fields available for changing:
*Total Bill amount for each line item should not be changed if fields Qty, Price or Tax were changed, otherwise you will see a message:
One note: Bill editing is only available in the very first step of approval process. It is designed this way to ensure compliance — that Bill is not changed after it is approved by a particular approver.
*There is an Item Description change feature under Beta key now available on request. Please contact us on firstname.lastname@example.org if you’d be interested to give it a try.