To ensure that file uploads work our app turns off ajax carts (the carts that popup when you add a product to the cart), and Shopify’s Dynamic Checkout Buttons (Paypal Buy it now buttons).
To test that everything is working correctly, checkout with a file uploaded for a product.
Next, test to see if the file upload gets added to your cart and checkout page.
If everything is working properly it will show up as a clickable link in the checkout page.
If it doesn’t show up, or is just text without a link to the file, your theme deletes the information before it gets to the cart.
Check to make sure that our settings to override ajax cart is turned “On“.
Settings > Override Ajax Cart > On
Test again and see if the file gets saved in the checkout page.