I have a database with the following columns

Data | timeAdded | status
a    | 2022-01-05T00:00:00.0000 | sent
a    | 2022-01-05T00:10:00.0000 | received
a    | 2022-01-05T00:17:00.0000 | sent
a    | 2022-01-05T11:21:00.0000 | sent
a    | 2022-01-05T11:29:00.0000 | received
b    | 2022-01-05T15:09:00.0000 | sent
a    | 2022-01-05T17:29:02.0000 | rejected
b    | 2022-01-05T18:09:30.0000 | sent

The timeAdded column is a type of string. I need a sql query to find count for how many times data ‘a’ occured in each 30 mins, throughout a day.
so the result would be

Data | Time                     | count
a    |2022-01-05T00:00:00.0000  | 3
a    |2022-01-05T00:30:00.0000  | 0
a    |2022-01-05T01:00:00.0000  | 0
            .
            .
            .
a    |2022-01-05T11:00:00.0000  | 2   

and so on for 24 hours.