You can create new Billing Runs by clicking on the Billing Run section.
You can also create a new billing run at the same time you create invoices from Unbilled. Or choose from one of the Billing Runs created previously.
When creating invoices from Unbilled, you will be prompted to select which draft billing run you would like to add the invoices to. These invoices will inherit the invoice created to date that is set when you add a new billing run.
When all invoices are approved, you can post (send or export) all the invoices at once. You can also individually send or export a single invoice by clicking on the invoice in the billing run or navigating to the invoice section.