PO Approval: Condition to judge PO Line price is increased in the PO Change Order

Summary

PO Approval: Condition to judge PO Line price is increased in the PO Change Order

Content

My ct want to Auto-Reject a PO change order approval request,
when the PO Line price is increased.
.
How can we enable this requirement?
Which attribute should we need to set when creating an approval rule for this condition?

I find there are attributes "Agreed Price Change Percent", and "Price Change Percent" in the dimension of "Document Line".

But it seems these attributes are not working. Are these attributes for this kind of requirement?

If yes, what kind of values are stored in these attributes?