Convert number(Amount) to words

how to i convert sum amount in to word as per below function

        $Cash_Sales=CashSales::with('customer_credit','items','store','supplier')
        ->select('vch_no','cash_c_id','l_type','created_at',DB::raw('sum(amount) as totalM'))
        ->where('l_type', 'cash_sale')
        ->groupby('vch_no','l_type','cash_c_id','created_at')
        ->get();

i want to display totalM in words, what code can i add there