SharePoint Online: Find All Sites with Unique Permissions using PowerShell

#Load SharePoint CSOM Assemblies
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

#Function to call a non-generic method Load
Function Invoke-LoadMethod() {
   param([Microsoft.SharePoint.Client.ClientObject]$Object = $(throw "Please provide a Client Object"),[string]$PropertyName) 
   $ctx = $Object.Context
   $load = [Microsoft.SharePoint.Client.ClientContext].GetMethod("Load") 
   $type = $Object.GetType()
   $clientLoad = $load.MakeGenericMethod($type)  
   $Parameter = [System.Linq.Expressions.Expression]::Parameter(($type), $type.Name)
   $Expression = [System.Linq.Expressions.Expression]::Lambda([System.Linq.Expressions.Expression]::Convert([System.Linq.Expressions.Expression]::PropertyOrField($Parameter,$PropertyName),[System.Object] ), $($Parameter))
   $ExpressionArray = [System.Array]::CreateInstance($Expression.GetType(), 1)
   $ExpressionArray.SetValue($Expression, 0)
   $clientLoad.Invoke($ctx,@($Object,$ExpressionArray))
}

#Define Parameter values
$SiteURL="https://crescent.sharepoint.com"

#Setup Credentials to connect
$Cred= Get-Credential
$Credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.Username, $Cred.Password)

Try {
    #Function to check if site has unique permissions
    Function Check-SPOWebUniquePermissions($SiteURL)
    {
        #Set up the context
        $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($SiteURL)
        $Ctx.Credentials = $credentials
 
        $Web = $Ctx.Web
        $Ctx.Load($Web)
        $Ctx.Load($Web.Webs)
        $Ctx.ExecuteQuery()

        #Check if the site has unique permissions
        Invoke-LoadMethod -Object $Web -PropertyName "HasUniqueRoleAssignments"
        $Ctx.ExecuteQuery()

        if ($Web.HasUniqueRoleAssignments -eq $true)
        {        
            Write-Host -f Green "Site '$($Web.URL)' has Unique Permissions"
        }
        else
        {
            Write-Host -f Yellow "Site '$($Web.URL)' is inhering Permissions from the Parent"
        }
 
        #Process Each subsite in current site
        ForEach($Web in $Web.Webs)
        {
            #call the function recursively
            Check-SPOWebUniquePermissions $Web.Url
        }
    } 
    #call the function 
    Check-SPOWebUniquePermissions $SiteURL
}
Catch {
    write-host -f Red "Error Checking Unique Permissions!" $_.Exception.Message
}