$revenueMonth = Callback::where('created_at', '>=', Carbon::today()->startOfMonth()->subMonth())->sum('payment');

$revenueMonth = Callback::whereMonth(
    'created_at', '=', Carbon::now()->subMonth()->month
);

$revenueMonth = Callback::where(
    'created_at', '>=', Carbon::now()->subDays(30)->toDateTimeString()
);

$revenueMonth = Callback::where(
    'created_at', '>=', Carbon::now()->firstOfMonth()->toDateTimeString()
);

$revenueMonth = Callback::where(
    'created_at', '>=', Carbon::now()->startOfMonth()->subMonth()->toDateString()
);

$revenueMonth = Callback::where(
    'created_at', '>=', Carbon::now()->subMonth()->toDateTimeString()
);

$fromDate = Carbon::now()->subMonth()->startOfMonth()->toDateString();
$tillDate = Carbon::now()->subMonth()->endOfMonth()->toDateString();

$revenueLastMonth = Callback::whereBetween(DB::raw('date(created_at)'), [$fromDate, $tillDate])->get();

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$fromDate = Carbon::now()->subMonth()->startOfMonth()->toDateString();
$tillDate = Carbon::now()->subMonth()->endOfMonth()->toDateString();

$revenueLastMonth = Callback::whereBetween('created_at',[$fromDate,$tillDate])->get();