Update apis/chat_api.py

apis/chat_api.py

@@ -126,7 +126,7 @@ class ChatAPIApp:
 
     class QueryRequest(BaseModel):
         input: str
-        model: str = Field(..., example="bert-base-uncased")
+        model: str = Field(default="bert-base-uncased")
         encoding_format: str
 
     class ChatCompletionsPostItem(BaseModel):