Many times it happens that the customer has ordered more than one product and some products you have ready for shipment while orders will take time, in this case, we generally do partial shipping on Shopify. So this kind of invoice will not get auto-created.
When you have partially fulfilled an order on Shopify. Check the image and do the needed steps in order to download the Invoice.
Shopify Order View for your easy reference.
Now, from our GST Invoice India Order section if you directly download the invoice, it will show all 5 items in the invoice, but as you just fulfilled 2 items you can not send all 5 as fulfilled to your customer, so what you need to do is, click on "Update only Partially/Multiple Fulfilled Orders"
On Clicking that button it will ask how you want to divide shipping in order, i.e. whether you want to divide shipping equally between all items or want to take full shipping in these partial orders. See the image for further explanation.
Now as you decided on how to split Shipping amount, you can click submit and then click, Download Only Partial/Multifulfillment orders" Button. See image
So like this when you fulfilling remainin item repeat the process and get your invoice downloaded.
Hope its clear, and if you still have any issues contact us on live chat.