WF: Notify the creator only if the last approval

Hello,

I am setting up a workflow (copy of WF_PO_REL) for the validation of purchase orders,

For the creator of the purchase order after each approval by an approver, he receives a notification in the workplace (task: TS20000168).

My question is how I can activate the notification to the creator only if it is the last approval (= purchase order launched), and not after each approval.

For example in a purchase order if it requires 3 approval, the creator must not be notified in the workplace until after the third approval

Thanks.