Once you have created a Resource for your sale, you can then create (and send) an invoice straight to the customer.
To create an invoice in Xero through Ninjodo:
Step 1 - Click [Create Xero Invoice]
From the resource detail page, click on [Create Xero Invoice] below the Revenue items towards the middle of the page
Note: You may be redirected to authorise with Xero, this is normal to update your account with new security access
Step 2 - Update the Details for the Invoice
Once the invoice box is open, you can adjust the settings for the invoice.
Options you can change:
Step 3 - Click "Create Invoice" or "Create & Send Invoice"