When using a custom template for a tracking pixel, how can you ensure that sensitive API keys or account IDs are not exposed in the client-side code?

When using a custom template for a tracking pixel, you can ensure that sensitive API keys or account IDs are not exposed in the client-side code by avoiding hardcoding them directly into the template. Instead, implement a server-side lookup or use environment variables to retrieve these values dynamically. The preferred method is to use server-side lookups. Create a Google Cloud Function or similar serverless function that securely stores the API keys. The custom template then makes an HTTPS request to this function, passing any necessary parameters (e.g., account ID). The cloud function authenticates the request, retrieves the API key, and returns it to the template. The template then uses the API key to configure the tracking pixel. This ensures that the API key is never directly exposed in the client-side code. Another method is to use environment variables. If your server-side tagging environment supports environment variables, you can store the API keys as environment variables. The custom template can then access these environment variables at runtime to configure the tracking pixel. The environment variables are stored securely on the server and are not exposed to the client. Finally, never include the API key as a direct input field in the template editor. Instead, use a generic input field (e.g., 'configuration ID') and then map this input to the API key on the server-side using a lookup table or environment variable. By implementing these techniques, you can protect sensitive API keys and account IDs from being exposed in the client-side code, reducing the risk of unauthorized access or misuse.