Public/Graph/GraphIdentities/Get-GraphUnifiedRole.ps1

function Get-GraphUnifiedRole {
    [CmdletBinding()]
    param (
    )
    if ([datetime]::UtcNow -ge $TimeToRefresh) { Connect-PoshGraphRefresh }
    $RestSplat = @{
        Uri     = 'https://graph.microsoft.com/beta/roleManagement/directory/roleDefinitions'
        Headers = @{ "Authorization" = "Bearer $Token" }
        Method  = 'Get'
    }
    Invoke-RestMethod @RestSplat -Verbose:$false | Select-Object -expandproperty Value

}