Fixed error

app.py

@@ -11,10 +11,10 @@ iface = gr.Interface(
     fn = kmer_tokenizer,
     inputs=[
         gr.Textbox(label="SMILES"), 
-        gr.Number(label="ngram", default=4, step=1),
-        gr.Number(label="stride", default=1, step=1),
-        gr.Checkbox(label="Remove Last", default=False),
-        gr.Textbox(label="Exclusive Tokens (comma-separated)", default="", optional=True)
+        gr.Number(label="ngram", value=4),
+        gr.Number(label="stride", value=1),
+        gr.Checkbox(label="Remove Last", value=False),
+        gr.Textbox(label="Exclusive Tokens (comma-separated)", value="")
     ],
     outputs="text"
 )