Update app.py

app.py

@@ -38,7 +38,7 @@ generation_model = GenerativeModel(config["model"])
 def wandb_log(prompt, completion):
     wandb.login(key = wandb_api_key)
     wandb.init(project = "vertex-ai-llm", config = config)
-    wandb.log({"prompt": prompt, "completion": completion})
+    wandb.log({"prompt": str(prompt), "completion": str(completion)})
     wandb.finish()
 
 def invoke(prompt):