Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Financial.php
public static function PMT($rate = 0, $nper = 0, $pv = 0, $fv = 0, $type = 0)
    {
        $rate = Functions::flattenSingleValue($rate);
        $nper = Functions::flattenSingleValue($nper);
        $pv = Functions::flattenSingleValue($pv);
        $fv = Functions::flattenSingleValue($fv);
        $type = Functions::flattenSingleValue($type);

        // Validate parameters
        if ($type != 0 && $type != 1) {
            return Functions::NAN();
        }

        // Calculate
        if ($rate !== null && $rate != 0) {
            return (-$fv - $pv * pow(1 + $rate, $nper)) / (1 + $rate * $type) / ((pow(1 + $rate, $nper) - 1) / $rate);
        }

        return (-$pv - $fv) / $nper;
    }
public static function PMT($rate = 0, $nper = 0, $pv = 0, $fv = 0, $type = 0)
    {
        $rate = Functions::flattenSingleValue($rate);
        $nper = Functions::flattenSingleValue($nper);
        $pv = Functions::flattenSingleValue($pv);
        $fv = Functions::flattenSingleValue($fv);
        $type = Functions::flattenSingleValue($type);

        // Validate parameters
        if ($type != 0 && $type != 1) {
            return Functions::NAN();
        }

        // Calculate
        if ($rate !== null && $rate != 0) {
            return (-$fv - $pv * pow(1 + $rate, $nper)) / (1 + $rate * $type) / ((pow(1 + $rate, $nper) - 1) / $rate);
        }

        return (-$pv - $fv) / $nper;
    }
PMT.

Returns the constant payment (annuity) for a cash flow with a constant interest rate.

@param float $rate Interest rate per period
@param int $nper Number of periods
@param float $pv Present Value
@param float $fv Future Value
@param int $type Payment type: 0 = at the end of each period, 1 = at the beginning of each period

@return float