Hi,

For this you have to create a new field in account.move model for your new field serviced organization. After that you can pass the value from sale order to invoice using _prepare_invoice function

try as below :

class SaleOrder(models.Model):
_inherit = 'sale.order'

def _prepare_invoice(self):
result = super(Sale, self)._prepare_invoice()
result.update({
'field_in_invoice': ​self.service_organization,
})

return result

Refer this video for more details: How To Pass New Field Value From Sale Order To Invoice In Odoo

Hope this will help you

Thanks