GTMetrix is suggesting to use a CDN when I already have Cloudflare

I am integrated to Ezoic through my Cloudlare account for both of my websites. Yet, when I run speed tests for my blog posts on GTMetrix, I’m getting terrible speed scores with a main suggestion from GTMetrix that I use a CDN. But my websites already use Cloudflare. So why is GTMetrix still showing poor speed scores / suggesting to use a CDN? What’s missing in my configurations???