Export to csv attributes that are nested/json - AzureAD Logs

I am trying to generate a report through powershell from Get-AzureADAuditDirectoryLogs and export it to a CSV. The report will need to grab JSON attributes as follow
Result, ResultReason, InitiatedBy (DisplayName & UserPrincipalName), TargetResources (DisplayName), AdditionalDetails (StartTime, ExpirationTime)