Request no referer

在访问cloudflre代理的网站时,其中的图片链接会发送请求直接到我的caddy服务器(没有使用Cloudflare cdn),这个请求没有referer,如果我取消代理直接访问,那就会正常携带referer,如果不携带referer那我的caddy就会拒绝请求,导致我的网站上图片都看不到了,为什么Cloudflare会让referer请求消失,我试过用Transform Rules的HTTP Request Header Modification,依然不能把请求头加上
When visiting a Cloudflare proxy website, the image link will send a request directly to my caddy server (Cloudflare cdn is not used). This request does not have a referer. If I cancel the proxy direct access, I will normally carry a referer. If I do not carry a referer, my caddy will reject the request, causing the images on my website to be invisible. Why does Cloudflare make the referer request disappear, I have tried to use HTTP Request Header Modification of Transform Rules, but I still cannot add the request header