Cloudflare Tunnels use Cloudflare's proxy, which only supports proxying HTTP Traffic. If you want to use non-http applications over your tunnel, Cloudflare has a few other options:
Please note for all of these except SSH and VNC which can be browser-rendered, you will either need to use cloudflared (Cloudflare's tunnel daemon) on the client machine running in the background or Private Networking with WARP, and have WARP installed on the client machine logged into your Zero Trust Team.