Dynamic API Key issue

I have created new function in Appwrite cloud. In function I using below code to initialize Appwrite client

const client = new Client() .setEndpoint(config.APPWRITE_ENDPOINT) .setProject(config.APPWRITE_PROJECT_ID) .setKey(req.headers['x-appwrite-key']);

But I am can see error in Appwrite function execution logs: "Appwrite API key not configured".

I am executing this function from React project using below code: functions.createExecution();

Why dynamic API key is not working? Am I missing anything here?

Thanks