Hi there Frank Luo
Thasts good question and thanks for using QandA platform.
For this limiting the responses to ur own data you can enable Limit responses, when enabled, the model attempts to only rely on your documents for responses. This is set to true by default.
Ill also provide you the documentation link below have a look at it
solution - I think I more or less figured it out. If I prefix EVERY question with "do not use your own knowledge.", it seems working.