How can I get a Audit report for activity on a Shared Mail file?

We have a need to get information on the activity on a shared mail file. We are using O365. I have Audit enabled. I have an E3 license so I know I will not be able to see everything but I should be able to see some activity. I ran the PS script -  Get-Mailbox -Identity <shared mail file identity>| Select-Object -ExpandProperty AuditDelegate I received a full list of properties.

In the Compliance Admin console I put in the share mail file name in the users field and get minimal information. I put the name in the File, folder or site field and get some information such as add mail box  or recipient permission.

I was hoping when I selected a date range when I know there was activity and put nothing in the user or file field and exported the report, I could search for the shared mail file name and see what activity was done. I can only see the add mail box  or recipient permission activity.

Can anyone assist me in getting the specific steps required to report the activity of a shared mail file such as when it was accessed and who accessed it?

thank you