In order to create a not derived non-refundable rate on log in to your Extranet. Go to Rates & Availability / Rates Plans:

Click on Add new rate plan:

Choose Non-refundable option:

In the point 5 make sure to choose Set as a new rate plan opion and click on Review:

Make sure that the rest of the settings is correct and click on Activate rate plan:

Now you should be able to map the rate in the system.