Hi Ben,
Once you activate the Flow Designer / Service Catalog Plugin you will have a new trigger option for Service Catalog:
After you create and save the flow with "Service Catalog" trigger you can then head to your Catalog Item and add the "Flow" field to the form. Make sure there are no values in the "Workflow" or "Execution Plan" fields then select your newly created flow in the "Flow" field:
Once you are back in your Flow you can add the action "Get Catalog Variables" and configure it to select your catalog item. Once your catalog item is selected in the "Template Catalog Item" you can then select the catalog variables to utilize in the flow like so:
After which the variables will be available in the "Data" section of the flow:
When the catalog item is submitted by an end user the variables will automatically be associated to the RITM and will show in the variable editor.
Hope this helps.
--David
