How do add an Order Type for orders?

I followed the following steps to add an order type:

Step 1:

I added a lookup code to:

Setup and Maintenance -> Manage Order Lookups -> Lookup Type: ORA_DOO_ORDER_TYPES

Step 2:

I created a new rule in:

Setup and Maintenance -> Manage Process Assignment Rules for Sales Orders

But when I was inputting the "IF" condition, when "is equal to" is selected, the dropdown list is not loading.

So I couldn't assign my newly-created Order Type to the new rule I created.

The newly-created Order Type isn't showing either when the dropdown list for Create Order is clicked:

Hoping for your assistance. Thank you!