Send POST request to HTTPS

Hello, I'm sending my post request to HTTPS page https://example.com/index.php?fc=module&module=mydemomodule&controller=display this way:

     IEnumerator CaptureScreenshotAndPost()
     {
         byte[] imageBytes = screenImage.EncodeToPNG();
         WWWForm form = new WWWForm();
         form.AddField("hello", "yellow");
         form.AddBinaryData("fileToUpload", imageBytes, "screenShot.png", "image/png");
         UnityWebRequest www1 = UnityWebRequest.Post("https://example.com/index.php?fc=module&module=mydemomodule&controller=display", form);
        
         yield return www1.Send();
 
         if (www1.isNetworkError || www1.isHttpError)
         {
             Debug.Log(www1.error);
         }
         else
         {
             Debug.Log("Upload completed!");
         }
 
     }

But getting the following error

 Mixed Content: The page at 'https://example.com/index.php?fc=module&module= mydemomodule&controller=display' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint 'http://example.com/index.php?fc=module&module= mydemomodule&controller=display?fc=module&module= mydemomodule&controller=display'. This request has been blocked; the content must be served over HTTPS.