Can AI be used in writing scientific papers?

I often use various online tools based on artificial intelligence when writing essays or performing other tasks at university. But I recently learned that the dishonest use of such technologies can be considered a violation of academic integrity and even lead to expulsion. Tell me, how exactly is the use of artificial intelligence regulated in teaching and scientific work? Is it always necessary to indicate that the text or a certain part was generated by AI, and what liability can there be if this is not done?