Question on PO DraftPurchaseOrder REST SUBMIT Action

Summary

During PO submit action we want to 'force validate' and 'bypass the approval' for the PO created using DraftPurchase order REST API

using the below payload , but threw 400 error

However with just 'validateBeforeSubmitflag ' only parameter passed, it went through, but it puts the document to 'pending Approval' (in this case no validation issue exists) and the another api call with 'bypassapprovalflags' fails with document already in ' pending approval' status

so how can we achieve , validation and bypass approval using 'submit' rest action ?