What is the problem with this code ... why it is returning nothing ..

I dotn have an access to log files but trying to access through function

readcsvlog(
csvPath:"logs/application_usage.csv",
filterColumName:"user",
filterOperator:"=",
filterValue:loggedInUser(),
timestampColumnName:"timestamp",
timestampStart:todatetime(today()-30),
timestampEnd:todatetime(today()),
headers:true()
)

why it is not returning anything