UPDATE

app.py

@@ -183,15 +183,15 @@ async def audio_effect_handler(event):
     audio_file = states[user_id]['audio']
 
     query = event.pattern_match.group(1).decode("UTF-8")
-    sound = Fusion.from_file(audio_file, format="mp3")
+    sound = await Fusion.from_file(audio_file, format="mp3")
     if query == 'slowed':
-        modified_sound = Fusion.effectSlowed(sound, 0.9)
+        modified_sound = await Fusion.effectSlowed(sound)
     elif query == 'speedup':
-        modified_sound = Fusion.effectSlowed(sound, 1.1)
+        modified_sound = await Fusion.effectSlowed(sound, 1.1)
     elif query == '8d':
-        modified_sound = Fusion.effect8D(sound)
+        modified_sound = await Fusion.effect8D(sound)
     elif query == 'reverb':
-        modified_sound = Fusion.effectReverb(sound)
+        modified_sound = await Fusion.effectReverb(sound)
     elif query == 'reverse':
         modified_sound = sound.reverse()
     else: