Assign number range to billing type

Go to tcode VOFA and assign the number range in the billing type.

Assign the number range as higlighted below.

Create output type for billing type

If you want system to automatically propose output type while you generating billing document, you need to set in using tcode VV31 and follow the steps as below:

Select the output type that you wanted to configure.

Put in the Sales Organization.

Set up all the Billing type that you want to auto propose.