Browser Caching on Google Cloud Platform

I think that there is a problem with caching when hosting Wordpress on Google Cloud.

This is the error I receive (website is quantitativealpha.com):
Browser Caching is not working properly:

- Your server may not have the "expires" module enabled (mod_expires for Apache, ngx_http_headers_module for NGINX)
- Another plugin may be interfering with the configuration

Do you have any idea how to fix this?
Thanks