【12:0†Name of File】- File Search function printing reference

Hello everyone.
I am using the File Search function in ChatGPT-4 via API.
The Assistant is returning the answer and at the end inserting a reference to the searched document.
How do I prevent the Assistant from printing this reference?

eg:
Response…【12:0†Name Doc】

I tried via prompt but it ignores and always prints the document name.
Thank you very much.