Now with variable usernames

ui.html

@@ -14,6 +14,9 @@
 <br>
 <button id="btn_create_session">Create session</button>
 <br><br><br>
+<input id="set_username" type="text" placeholder="New username" />
+<button id="btn_set_username">Set Username</button>
+<br><br><br>
 <input id="join_session_id" type="text" placeholder="Enter session id" />
 <button id="btn_join_session">Join session</button>
 
@@ -36,6 +39,15 @@
             body: JSON.stringify(data),
         })
     };
+    document.getElementById("btn_set_username").onclick = async function (e) {
+        let text = document.getElementById("set_username").value;
+        let data = {"username": text};
+
+        await fetch('api/change_username', {
+            method: 'POST',
+            body: JSON.stringify(data),
+        })
+    };
 </script>
 </body>