Update app.py

app.py

@@ -16,7 +16,7 @@ with scol:
     sselected_language = st.selectbox("Source language:", options, index=0, placeholder="Select source language")
 with tcol:
     tselected_language = st.selectbox("Target language:", options, index=1, placeholder="Select target language")
-model_name = st.selectbox("Select a model:", models, index=None, placeholder="Select language model")
+model_name = st.selectbox("Select a model:", models, index=0, placeholder="Select language model")
 
 sl = langs[sselected_language]  
 tl = langs[tselected_language]