WITH preparedData as(
SELECT
    userID,
    paymentAmount,
    paymentPeriod,
    paymentDateTime,
    EXTRACT(YEAR_MONTH FROM paymentDateTime) as paymentMonth,
    EXTRACT(YEAR_MONTH FROM DATE_ADD(paymentDateTime, INTERVAL paymentPeriod MONTH))
FROM
    payments
WHERE
     202101 BETWEEN EXTRACT(YEAR_MONTH FROM paymentDateTime) AND EXTRACT(YEAR_MONTH FROM DATE_ADD(paymentDateTime, INTERVAL paymentPeriod MONTH))
    AND paymentStatus = 1
    AND paymentPeriod > 0
    AND userID IS NOT NULL)

SELECT
 paymentPeriod,
 count(distinct userID)

FROM preparedData
GROUP BY paymentperiod
ORDER BY paymentPeriod