fix (#5482)

src/shell.html

@@ -179,7 +179,7 @@ jwE50AGjLCVuS8Yt4H7OgZLKK5EKOsLviEWJSL/+0uMi7gLUSBseYwqEbXvSHCec1CJvZPyHCmYQffaB
 
         <span id='controls'>
           <span><input type="button" value="📜 SOURCE CODE" onclick="location.href='https://github.com/raysan5/raylib';"/></span>
-          <span><input type="button" value="🖵 FULLSCREEN" onclick="Module.requestFullscreen(false, false)"></span>
+          <span><input type="button" value="🖵 FULLSCREEN" onclick="Module.canvas.requestFullscreen(false, false)"></span>
           <span><input type="button" id="btn-audio" value="🔇 MUTE" onclick="toggleAudio()"></span>
         </span>