List inactive Azure AD users

#Config Parameters
$InactiveDays = 30 # Past number of days user didn't login
$CSVPath = "C:\Temp\InactiveUsers.csv"
$InactiveUsers = @()
$ThresholdDate = (Get-Date).AddDays(-$InactiveDays)
$QueryStartDateTimeFilter = "{0:yyyy-MM-dd}T{0:HH:mm:sszzz}" -f $ThresholdDate
 
#Connect to Azure AD
Connect-AzureAD | Out-Null
 
#Get All users from Azure AD
$AllUsers = Get-AzureADUser -All $true
$TotalUsers = $AllUsers.Count
 
#Function to get the last login date time stamp of the user
Function Get-UserLastLogin([string] $UserObjectID)
{
    Try {
        Write-host -f Yellow "Collecting Last Login date of User Object:"$UserObjectID
 
        #Get Signin Logs of the user on specific time frame
        $SigninLog = Get-AzureADAuditSignInLogs -All:$true -Filter "userID eq '$UserObjectID' and status/errorCode eq 0 and createdDateTime ge $QueryStartDateTimeFilter" | Select -First 1
 
        #Return Last Login Date
        Return $SigninLog.CreatedDateTime
    }
    Catch {
        $message = $_
        If ($message -like "*Too Many Requests*")
        {
            Write-host "`tSleeping for 10 seconds due to throttling limitations..." -ForegroundColor Cyan 
            Sleep 10
            #Recursive function call to retry the entry that was throttled
            Get-UserLastLogin $UserObjectID
        }
        Else
        {
            Write-host $Message -ForegroundColor Red           
        }
    }
}
 
$Counter = 1
$AllUsers | ForEach-Object {
    Write-Progress -Activity "Checking Signin Logs:" -Status "Processing $($_.UserPrincipalName) ($Counter of $TotalUsers)" -PercentComplete (($Counter / $TotalUsers) * 100) 
    #Call the function to get sign-in log
    $LastLoginDate = Get-UserLastLogin $_.ObjectID
     
    #Collect data
    If(!$LastLoginDate -or ($LastLoginDate -and ((Get-Date $LastLoginDate) -lt $ThresholdDate)))
    {
        $InactiveUsers += [PSCustomObject][ordered]@{
            UserLoginName   = $_.UserPrincipalName
            UserDisplayName   = $_.DisplayName
        }
    }
    $Counter++
}
 
$InactiveUsers
 
#Export Data to CSV
$InactiveUsers | Export-Csv -Path $CSVPath -NoTypeInformation

## Crédito do script João Paulo Turbino
## https://www.linkedin.com/in/jo%C3%A3o-paulo-tur%C3%ADbio-ximendes-21a166255/