diff --git a/manim_voiceover/services/azure.py b/manim_voiceover/services/azure.py
index aa61bf8..202b897 100644
--- a/manim_voiceover/services/azure.py
+++ b/manim_voiceover/services/azure.py
@@ -1,13 +1,16 @@
 import os
-from pathlib import Path
 import sys
-from dotenv import load_dotenv, find_dotenv
+from pathlib import Path
+
+from dotenv import find_dotenv, load_dotenv
+from manim import logger
+
 from manim_voiceover.helper import (
     create_dotenv_file,
     prompt_ask_missing_extras,
     remove_bookmarks,
 )
-from manim import logger
+from manim_voiceover.services.base import SpeechService
 
 try:
     import azure.cognitiveservices.speech as speechsdk
@@ -16,7 +19,6 @@
         'Missing packages. Run `pip install "manim-voiceover[azure]"` to use AzureService.'
     )
 
-from manim_voiceover.services.base import SpeechService
 
 load_dotenv(find_dotenv(usecwd=True))
 
diff --git a/manim_voiceover/services/elevenlabs.py b/manim_voiceover/services/elevenlabs.py
index 0f94c9a..eb19d38 100644
--- a/manim_voiceover/services/elevenlabs.py
+++ b/manim_voiceover/services/elevenlabs.py
@@ -6,7 +6,8 @@
 from dotenv import find_dotenv, load_dotenv
 from manim import logger
 
-from manim_voiceover.helper import create_dotenv_file
+from manim_voiceover.helper import create_dotenv_file, remove_bookmarks
+from manim_voiceover.services.base import SpeechService
 
 try:
     from elevenlabs import Voice, VoiceSettings, generate, save, voices
@@ -17,9 +18,6 @@
     )
 
 
-from manim_voiceover.helper import create_dotenv_file, remove_bookmarks
-from manim_voiceover.services.base import SpeechService
-
 load_dotenv(find_dotenv(usecwd=True))
 
 
@@ -51,7 +49,7 @@ def __init__(
         voice_name: Optional[str] = None,
         voice_id: Optional[str] = None,
         model: str = "eleven_monolingual_v1",
-        voice_settings: Optional[Union[VoiceSettings, dict]] = None,
+        voice_settings: Optional[Union["VoiceSettings", dict]] = None,
         transcription_model: str = "base",
         **kwargs,
     ):
diff --git a/manim_voiceover/services/openai.py b/manim_voiceover/services/openai.py
index 263edac..025fc40 100644
--- a/manim_voiceover/services/openai.py
+++ b/manim_voiceover/services/openai.py
@@ -1,14 +1,16 @@
 import os
 import sys
 from pathlib import Path
+
+from dotenv import find_dotenv, load_dotenv
 from manim import logger
-from dotenv import load_dotenv, find_dotenv
 
 from manim_voiceover.helper import (
     create_dotenv_file,
     prompt_ask_missing_extras,
     remove_bookmarks,
 )
+from manim_voiceover.services.base import SpeechService
 
 try:
     import openai
@@ -18,7 +20,6 @@
         'Run `pip install "manim-voiceover[openai]"` to use OpenAIService.'
     )
 
-from manim_voiceover.services.base import SpeechService
 
 load_dotenv(find_dotenv(usecwd=True))