i think working

server.py

@@ -42,21 +42,21 @@ def off():
 @retry(stop=stop_after_attempt(5))
 def hello():
     print(request.args.get("rgb"))
-    # rgb = (request.args.get("rgb")
-    # r = int(request.args.get("r"))
-    # g = int(request.args.get("g"))
-    # b = int(request.args.get("b"))
-    # hex = rgb2hex(r, g, b)
-    # hex = hex.replace("#", "")
+    rgb = list(request.args.get("rgb"))
+    r = rgb[0]
+    g = rgb[1]
+    b = rgb[2]
+    hex = rgb2hex(r, g, b)
+    hex = hex.replace("#", "")
 
-    # str = "56" + hex + "00f0aa"
-    # result = subprocess.run(
-    #     [f"gatttool -i hci0 -b b2:3b:03:00:14:d6 --char-write-req -a 0x0009 -n {str}"],
-    #     stdout=subprocess.PIPE,
-    #     shell=True,
-    # ).stdout.decode("utf-8")
-    # print(result)
+    str = "56" + hex + "00f0aa"
+    result = subprocess.run(
+        [f"gatttool -i hci0 -b b2:3b:03:00:14:d6 --char-write-req -a 0x0009 -n {str}"],
+        stdout=subprocess.PIPE,
+        shell=True,
+    ).stdout.decode("utf-8")
+    print(result)
     if "Characteristic value was written successfully" not in result:
         raise Exception
     else:
-        return request.query_string
+        return hex