How to permanently delete chat conversation after scheduled meeting concludes with Teams Premium?

Hi

We use 'always logged' in Users in the meeting rooms, to run our Teams meetings.

I would like to delete the chat when a meeting ends due to security and privacy.

I know about retention policy's, the minimum is 1 day, this is not good enough.

I have upgrade to Teams Premium as I read that's the version you need to clear this data.

Does anyone know where this option is in the O365 suite?

Thanks in advance.