Show the Order Attribute in the creation of New Order in Admin Page

I have created an attribute for Orders through a module using the steps here http://www.thecoachsmb.com/how-to-add-order-attribute-in-magento-2/

But in the example given, the value is only added after the Order has been saved.

I wanted to have the attribute shown during the Creation of Order in the Admin Page, and would like it as a required field before saving the Order.