Make PO Number A Required Field In B2B Checkout

The merchant requires a PO number for all orders, so I’m trying to figure out if we can require the PO number to be populated during checkout.

I’m not seeing PO number as one of the available fields in the checkout validation function:

It would be possible to use Checkout Blocks to add a required field, populate it as a metafield and then use flow on the backend to populate the PO Number field from that metafield.

But the problem there is that there’s no way to disable the native PO Number field in checkout, so you’d have duplicate PO Number fields.

Can you try payment customisation extension?