Sandboxes are the environment for rapid web development.
When using Browser Sandboxes, your code is evaluated and run our built-in execution environment. These client environments run entirely inside of your browser and will continue to bundle your code even when you lose your connection to our servers.
Browser Sandboxes each have their own bundler attached to them which are configured to support a specific framework and emulate their official CLI tools. They are not one-to-one implementations and thus do not support advanced configuration like custom webpack configurations or ejecting. However, they are designed to mirror the default behavior of the framework.
If your project requires advanced configuration, try using a Cloud Sandbox instead.