1. Starting from your Shopify dashboard, click on Online Store, and then click on Themes.
2. Click the Actions button, then select Edit code.
Select Products from the dropdown menu in the header and then select a product template. The default product is the standard template for a theme.
Locate a section for product information in the left-hand toolbar. Then, hover below the variant picker, click + Add block, then select the Uploadery block on the Apps tab. If the block does not appear, then you are not using a 2.0 theme.
5. Don't forget to save your changes.
You can now start creating options with upload fields for your products.