<?php

function getYearsAndMonthsBetweenDates($startDate, $endDate) {
    $start = new DateTime($startDate);
    $end = new DateTime($endDate);
    $interval = new DateInterval('P1M');

    $periods = new DatePeriod($start, $interval, $end); // We add $interval to include the end month too
    $yearMonths = [];

    foreach ($periods as $period) {
        $yearMonths[] = $period->format('Y-m');
    }

    return $yearMonths;
}

$startDate = "2019-01-13";
$endDate = "2023-05-02";

$yearsAndMonths = getYearsAndMonthsBetweenDates($startDate, $endDate);

foreach($yearsAndMonths as $yearMonth) {
    echo $yearMonth . PHP_EOL;
}