Can supplier create an invoice from a timesheet in the Supplier Portal (self service)?

This is PeopleSoft Finance & Supply Chain 9.2 with PeopleTools 8.57.

I know that if PeopleSoft Service Procurement is installed, a supplier user can login to the PeopleSoft Supplier Portal to create and submit his time-sheets or progress logs for approval. I have already tested this in the DEMO environment and it works very well.

The timesheeet or progress log, once submitted, goes through a workflow approval. Once the time-sheet or progress log is approved, a PeopleSoft user in the Employee Portal can select the time-sheet or progress log in Service Procurement and generate an invoice. Once the invoice is approved, the voucher can be created via Voucher Build.