fix errors

app.py

@@ -177,9 +177,8 @@ with demo:
     with gr.Tabs():
         with gr.TabItem("Upload from disk"):
             uploaded_file = gr.Audio(
-                source="upload",  # Choose between "microphone", "upload"
+                sources=["upload"],  # Choose between "microphone", "upload"
                 type="filepath",
-                optional=False,
                 label="Upload from disk",
             )
             upload_button = gr.Button("Submit for separation")
@@ -197,9 +196,8 @@ with demo:
 
         with gr.TabItem("Record from microphone"):
             microphone = gr.Audio(
-                source="microphone",  # Choose between "microphone", "upload"
+                sources=["microphone"],  # Choose between "microphone", "upload"
                 type="filepath",
-                optional=False,
                 label="Record from microphone",
             )