如何在没有任何扩展名的php中保存图像

I have my image in the URL https:*******/MEb022d05131def325b861d8b9425519b2, I want to download the image on click of the image. How can I do that?

Most likely the Content-Type HTTP response header field will give you a hint when you request the URL. If the server is under your control however, you could determine the image type during the request is served and provide the extension or header yourself.