MAGENTO 2 AUTO INVOICE AND SHIPMENT
https://www.cynoinfotech.com/product/auto-invoice-and-shipment-magento-2-extension/

Therefore, customers can satisfy with your store’s automatic and quick order process and it’s especially used for offline payment methods. Magento 2 Auto Invoice and Shipment extension save time to create invoice manual and payment transaction. This extension generates invoice and shipment process to customers automatically after their order placed.
In Magento, there is not any functionality to create invoices and shipment invoices automatically. So admin needs to can create invoices and shipment invoice manually. And this process takes more time when a store has several orders. Magento 2 Auto Invoice and Shipment extension generates automatically with full information of invoice and shipment process. Magento2 extension Auto Invoice and Shipment helps to make the fastest order processing, and customers get a confirmation email to automatically send invoices and shipment.