Who is deleting files?

Hi Community. I am running a Nextcloud installation for our small company. Now it happened that somebody deleted a complete folder. I could restore but how can I find the person who did it?

I think a predefined function doesn’t exist yet, but you can run a SQL query to identify the user (assumption: files in directory “/Notes/...”), like e.g.:

SELECT type,user,file FROM oc_activity WHERE `type` = 'file_deleted' AND `file` LIKE "/Notes/%";

OK, thank you. That is too difficult for me. I am asking an IT guy to help me. However, I understand, a standard function is not available. I am surprised and I am thinking everybody wants to know why data are gone and who deleted, right?
Thank you for you quick response