How to set SSL for Google cloud wordpress

Sorry for the inconvenience.

I have an SSL only strain from Cloudflare.

I launch a wordpress site from google cloud WordPress Certified by Bitnami and Automattic.

How can I set up Cloudflare ssl on that wordpress site.

currently my wordpress site caigicungpost.com

when i attach ip to domain i get error message [521]

this is the error generated when i attach a new wordpress ip address created by google cloud WordPress Certified by Bitnami and Automattic.