Cloudflare cache status always dynamic

Hello everyone, I have a question about Cloudflare caching, could I ask for your advice here? There's an image URL in the project https://tv.cmsgo.eu.org/player/assets/login-Bez7HMPq.jpg, and this image never gets cached in Cloudflare; the cf-cache-status is always DYNAMIC. I've set up a cache rule, but it doesn't seem to be working.