I have Odoo 15 Community and I have created a custom field in the sale.order model called x_purchase_order and I want to be able to show that custom field in the account.move.form​.

I added a custom field to sale.order 

Field Name: x_purchase_order

Field Type: char

I cant seem to be able to connect use the field from sale.order in account.move.form. I have created a view to show the field in the sale.order.form but cannot figure out how to get the field to show up in account.move.form.

Architecture
xpath expr="//field[@name='date_order']" position="after"
    field name="x_purchase_order"
xpath