fix: back to option of providing custom api key

app.py

@@ -17,7 +17,7 @@ def generate_voice(text, voice_name, model_name, api_key):
             text, 
             voice=voice_name, 
             model=model_name, 
-            api_key=None # api_key if api_key != '' else None #
+            api_key=api_key if api_key != '' else None
         )
     except UnauthenticatedRateLimitError as e:
         raise gr.Error("Thanks for trying out ElevenLabs TTS! You've reached the free tier limit. Please provide an API key to continue.") 

requirements.txt

@@ -1 +1 @@
-elevenlabs 
+elevenlabs==0.2.15