Replace NULL with the Date in the WHERE clause in Mysql

So, in order to get 0s in my count column I have tried out this query which works.

SELECT b.TXT_RECORD_DATE, a.TXT_CALL_TYPE, 
      SUM(CASE 
        WHEN b.TXT_CALL_TYPE IS NOT NULL
          THEN 1
        ELSE 0
      END) AS StatusCount
FROM (
  SELECT DISTINCT TXT_CALL_TYPE
  FROM CDR
  ) a
LEFT JOIN CDR b ON a.TXT_CALL_TYPE = b.TXT_CALL_TYPE AND b.TXT_RECORD_DATE IN ('2022-04-12', '2022-04-13','2022-04-14')
GROUP BY a.TXT_CALL_TYPE, b.TXT_RECORD_DATE;

But it shows [NULL]s in the columns where StatusCount = 0

So my question is that is there a way to actually assign the date that is being currently searched instead of the [NULL]

The current result looks like this

Sorry if I forgot anything or was not clear. I'm writing to you in the middle of the night and is so tired. Thanks Anyways. You guys are always awesome.

You need to generate a list of the dates you are interested in and CROSS JOIN that to the list of call types; then you can LEFT JOIN that to the call records to get the result you want. In MariaDB you can make use of the sequence storage engine to easily generate a list of the dates:

SELECT d.TXT_RECORD_DATE, a.TXT_CALL_TYPE, 
      SUM(CASE 
        WHEN b.TXT_CALL_TYPE IS NOT NULL
          THEN 1
        ELSE 0
      END) AS StatusCount
FROM (
  SELECT '2022-04-12' + INTERVAL (seq) DAY AS TXT_RECORD_DATE
  FROM seq_0_to_2
) d
CROSS JOIN (
  SELECT DISTINCT TXT_CALL_TYPE
  FROM CDR
  WHERE TXT_CALL_TYPE IS NOT NULL
) a
LEFT JOIN CDR b ON a.TXT_CALL_TYPE = b.TXT_CALL_TYPE AND d.TXT_RECORD_DATE = b.TXT_RECORD_DATE
GROUP BY d.TXT_RECORD_DATE, a.TXT_CALL_TYPE

Demo on dbfiddle