Report room mailbox usage summary

Connect-ExchangeOnline
Connect-MgGraph -AppId $AppId -TenantId $TenantId -CertificateThumbprint $CertThumbprint

param(
    [string] $TenantId = "",
    [string] $AppId = "",
    [string] $CertThumbPrint = "",
    [string] $StartDate = (Get-Date).AddMonths(-6),
    [string] $EndDate = (Get-Date).AddMonths(6)
)
 
$CertThumbprint = '0CF6CE3F3548FD73E7AC8CF20226ED447E125C71'
 
# Connect to Exchange Online and then to the Graph using app-only mode
Connect-ExchangeOnline
Connect-MgGraph -AppId $AppId -TenantId $TenantId -CertificateThumbprint $CertThumbprint
 
# Use Exchange Online to Find Mailboxes
[array]$RoomMailboxes = Get-ExoMailbox -RecipientTypeDetails RoomMailbox -ResultSize Unlimited
# Set date range to check for
 
ForEach ($RoomMailbox in $RoomMailboxes) {
    Try {
        Write-Host ("Getting calendar events for room mailbox {0}..." -f $RoomMailbox.DisplayName)
        [array]$Events = Get-MgUserCalendarView -UserId $RoomMailbox.PrimarySmtpAddress -All -StartDateTime $StartDate -EndDateTime $EndDate -ErrorAction Stop
    } Catch {
        Write-Host ("Couldn't get calendar events for room mailbox {0} - check the error message" -f $RoomMailbox.DisplayName)
    }
    If ($Events) {
        Write-Host ("{0} events found for {1}" -f $Events.count, $RoomMailbox.DisplayName)
    }
}