Once you've upgraded to the new Commerce Customer Notifications editor, the consumer-side notifications are easier to customise but the merchant-side notifications are considered part of Squarespace's application interface and aren't designed to be customisable by us. In short, you cannot change the printed invoice.
The business address immediately follows the "order summary" content without any margins, so if you don't have any custom checkout fields then it will be just below the order total, as shown in your screenshot. We can't change this so you'll want to get in touch with Squarespace Customer Care. This may be something that @Leo_Lou or @kkaiser may want to know about.
If you're printing via the browser then a temporary workaround may be to add the required CSS using a browser extension, but I appreciate this is a little above and beyond! For example:
.sqs-order-summary-rendered-content {
margin-bottom: 34px;
}
