HTTPS cert for Firefox Preview

I'm using the new Firefox Preview on Android (, and was wondering if installing the cert is needed. I forgot about it for a while, and while using Firefox Preview I didn't notice ads. Is the cert really needed for it? Does it even install when tried? Also on the address for it why is it delivered via HTTP, and not HTTPS? Screenshot below from attempting at installing it into the Firefox Preview browser. I don't know if it even worked.

Boo Berry

Moderator + Beta Tester
Yes, the certificate is needed for HTTPS filtering. Currently Firefox Preview and Firefox Focus lack support for installing certificates into the browser, so HTTPS filtering isn't possible for them at the moment. AG for Android can filter HTTP in those browsers, but not HTTPS.