If you are following a customization article or installation instructions from third-party apps or Shopify, you may be looking for a theme.js, custom.js, or theme.js.liquid file.
Out of the Sandbox themes do not contain these files, but instead contain an app.js.liquid file which contains much of the JavaScript for the theme. The app.js.liquid file can be located by going into Online store > Themes > Actions > Edit code > Assets.
For more information on the template file structure for the Flex theme, check out our Development Guide.
JavaScript files do not maintain a running version history. This means that you cannot revert to an older version, so it's recommended you download the theme as a backup or duplicate your theme to create a version to test with.
If you require further assistance on integrating third-party code, we recommend reaching out to a Shopify Expert.
Informational Guide Only
This article is provided for informational purposes only and is not supported by Out of the Sandbox support. For further assistance with this, please contact third-party developer for assistance.