In case it completely dies there are archives now available:

http://web.archive.org/web/20210712193555/http://fxip.as2034...

https://archive.is/5a44i

Or the whole thing is small enough to fit in a comment:

  > GET / HTTP/1.1
  > Host: fxip.as203478.net
  > User-Agent: curl/7.76.1
  > Accept: */*
  > 
  * Mark bundle as not supporting multiuse
  * HTTP 1.0, assume close after body
  < HTTP/1.0 200 OK
  < Server: uIP/1.0 http://www.sics.se/~adam/uip/
  < Connection: close
  < Content-type: text/html
  < 
  <!DOCTYPE html>
  <html>
  <head>
   <title>Casio fx-9750GII Webserver</title>
   <link href="https://fonts.googleapis.com/css2?family=Lato&display=swap" rel="stylesheet">
   <style type="text/css">
    * {
     margin: 0;
     padding: 0; 
    }
  
    *:focus 
    {
     outline: none; 
    }
  
    *::-moz-focus-inner 
    {
     border: 0; 
    }
  
    body 
    {
     background: #fafafa;
     font-family: "Lato", sans-serif;
     font-size: 100%; 
     text-align: center;
    }
  
    a 
    {
     color: #0075BF; }
     a:not(:hover):not(:focus):not(:active) {
     text-decoration: none;
    }
  
  </style>
  </head>
  <body>
   <br>
   <h1>Casio fx-9750GII Webserver</h1><br>
   Welcome! 
   This page is hosted on an Casio fx-9750GII graphical calculator, running a SuperH SH4 processor.<br>
   It's running a port of the uIP TCP/IP stack, using SLIP over the 3pin 2.5mm serial port.<br>
   <br>
   <a href="https://github.com/Manawyrm/fxIP" target="_blank">Firmware (uIP port, webserver implementation)</a>
   <br><br>
   <img src="https://screenshot.tbspace.de/vfscewyjzir.jpg" style="width: 700px;"><br>
   <img src="https://screenshot.tbspace.de/ijlnydgsvkw.jpg" style="width: 700px;"><br>
   <i>(these pictures are not hosted on the calculator.)</i>
   <br><br>
  </body>
  </html