chunks.ps1

if($membersToAdd.Count -gt 0){
    Write-Host("Writing membersToAdd")
    
    $chunkArr = $membersToAdd
    $chunks = [System.Collections.ArrayList]::new()
    for ($i = 0; $i -lt $chunkArr.Count; $i += 20) {
        if(($chunkArr.Count - $i) -gt 19) {
            $null = $chunks.add($chunkArr[$i..($i + 19)])
        }else{
            $null = $chunks.add($chunkArr[$i..($chunkArr.Count - 1)])
        }
    }
    Write-Host("membersToAdd: Split Members into $($chunks.count) as we can only push 20 per batch")
    $count = 1
    foreach ($chunk in $chunks) {
        Write-Host("membersToAdd: Processing Chunk $count of $($chunks.Count)")
        Invoke-WebRequest -UseBasicParsing -Uri "https://graph.microsoft.com/v1.0/groups/$backupGroupId" -Headers $Headers -Method Patch -ContentType 'application/json' -Body (@{
                "members@odata.bind" = $chunk
        } | ConvertTo-Json)
        $count++
    }
}