Supplier not receiving PO Acknowledgement Notification

Summary

Supplier not receiving PO Acknowledgement Notification

Content

Hi,

We have enabled Supplier Acknowledgement on PO level. However, once the PO is approved, Supplier should be able to receive notification/email to acknowledge the PO. 

We are receiving notifications for other events like PO approval, req approval. But we are not getting notification in the supplier portal to acknowledge the PO. 

Are we missing any steps?