Automatic invoicing will send an invoice on the day you select to your customer by the method you select.
To enable this, click the customer button on the left menu. On the main customer screen click the customer you want to edit by clicking the pencil icon to the far right of their name.
Once on the customer screen, check the checkbox to “automatic invoicing”. Once enabled, you can choose the day of the month you want your invoice to be sent to this customer and how you want it sent.