Business want to approve purchase order automatically if any Purchase order is linked with BPA/CPA

Summary:

SR#3-31194911201

Business want to approve purchase order automatically if any Purchase order is linked with either Blanket Purchase Agreement or Contract Purchase agreement.

When we are trying to create approval rule for the same, in list of attributes for selection we are not able to find any attribute which has agreement on a PO

in approval rules, we are not able to see any attribute for agreement. we need to create an approval rule which should perform action based on agreement defined in purchase order.

Ex: If there is any BPA/CPA attached to a purchase order, then Purchase order should auto approve. but we are not able to see agreement field to add in condition