Unfortunately, you can not download all your invoices at once.
You can only download 50 invoices at once. The 50-order limit is something that Shopify controls, and apps, unfortunately, cannot change that limit.
Important Note: Because of Shopify’s API limits, Processing 50 invoices at once may seem slow. If you add additional data, it may take too long to process or it may not print the information as you expected. The most common solution for that is to hide the product images. It may speed up the whole process at once. After turning off product pictures, if you are still having issues in the batch process, you can try to turn off product variants or additional product details like meta fields or properties.
We suggest using our Google Drive, Dropbox, or FTP upload feature to automatically upload your invoices during the month. In this way, you are able to reach all your invoices at once without any issues.