If CORS isn't set up properly, you're likely to get errors that look like the above.
Cross-Origin Resource Sharing (CORS) is a way to let applications running on one domain access content from another domain, for example, letting yourdomain.com make requests to region-project.cloudfunctions.net/yourfunction.
Ensure that CORS is correctly set. This would resolve the error.
Hope it works!!
If you want to become a professional Google Cloud Architect, Its recommended to go for the certification course first.