Added callback manager handler

app.py

@@ -33,7 +33,10 @@ embed_model = NVIDIAEmbeddings(
 def custom_resolve_embed_model(embed_model):
     if isinstance(embed_model, NVIDIAEmbeddings):
         return embed_model
-    return resolve_embed_model(embed_model)
+    embed_model = resolve_embed_model(embed_model)
+    if not isinstance(embed_model, NVIDIAEmbeddings):
+        embed_model.callback_manager = Settings.callback_manager
+    return embed_model
 
 reranker = NVIDIARerank(
   model="nvidia/nv-rerankqa-mistral-4b-v3",