Approver Signature on Purchase Order

We are on Fusion Cloud. Our POs were created with BI Publisher, but we need to have the printed approver signature appear on the PO. We just need to show the approvers name, no signature is actually required. The signature needs to change by Bill To. Where would we store the signature that should appear on the Purchase Order? Since our Oracle Apps are hosted on Oracle's server would it be able to find the signature if we placed it on a local server?