After a customer accepts the proposal, you receive a purchase order (PO) that confirms you can execute the project.
You can add the PO number to the relevant quote for the accepted proposal and reference it on the invoices sent for project payment.
You need the "Manage quote PO number" permission in the "Opportunities" permissions group, or you need to be a member of a group that has it, to add, update, or delete the PO number.
To add the PO number:
1/ Go to the Quote Details view.
2/ Click the 3-dot menu and click "Settings > General."
3/ Add the PO number in the "Purchase Order" text box.
You can update or delete the PO number if needed. Cloud tracks all activity related to the PO number in the opportunity's activity log.