Ability to add PO Owner to approval flow

We have recently started using Ramp Procurement to generate PO’s.
On the Bill Pay side, we were able to add “PO Owner” as an approver into the process - so when a bill is attached to a PO it brings in the right person.
Procurement allows virtual cards and funds to be created - but adding “PO Owner” to the “Expense Reviews” approval flow is not an option but should be.
Thanks!