I successfully implemented SSL/https for my bitnami discourse website hosted on GCP following your advice/link given here above.
But, it still shows a yellow exclamation mark over green lock icon in the url bar, indicating 'Parts of the page are not secure'. Even though I've not changed anything at all in the bitnami implementation till this moment.
My website in question is: https://bathindahelper.xyz/ (sometimes I close this instance when it is night time in India).
Also, when I type bathindahelper.xyz, my FF doesn't auto redirects to https version. While with other websites, it does this ok.