[...]

var period = 31d //Tried 1mo here but is not working.
var data = batch
    |query('SELECT "tps_peak", "t_license_exceeded" FROM "' + db + '"."' + rp + '"."' + measurement + '" ')
        .period(period)
        .cron('0 0 1 * *') //1st day of each month.
    |where(lambda: ("t_license_exceeded" == 'true'))
    |count('tps_peak')
        .as('tps_peak_count')