Update asr.py

asr.py

@@ -43,6 +43,10 @@ def transcribe(
     audio_fp = (
         file_upload if "upload" in str(audio_source or "").lower() else microphone
     )
+    
+    if audio_fp is None:
+        return "ERROR: You have to either use the microphone or upload an audio file"
+    
     audio_samples = librosa.load(audio_fp, sr=ASR_SAMPLING_RATE, mono=True)[0]
 
     lang_code = lang.split()[0]