How to extract Nested Json Keys in Mariadb?

Question

I have this json file

{
  "data": {
    "Header": {
      "num": 1000095371,
      "name": "1000095371 LE"
    },
    "character": {
        "b1234": {
          "ID": 1
        },
        "b1256": {
          "ID": 2
        },
        "b12389": {
          "ID": 3
        }
      }
  },
  "id": 123456,
}

I want to extract like this

+--------+------------+---------------+--------------+-------------+
| id     | num        | name          | characterkey | characterid |
+--------+------------+---------------+--------------+-------------+
| 123456 | 1000095371 | 1000095371 LE | b1234        | 1           |
+--------+------------+---------------+--------------+-------------+
| 123456 | 1000095371 | 1000095371 LE | b1256        | 2           |
+--------+------------+---------------+--------------+-------------+
| 123456 | 1000095371 | 1000095371 LE | b12389       | 3           |
+--------+------------+---------------+--------------+-------------+

so the nested values inside character will be dynamic like it may have dynamic characterkey and count as well. I am able to extract all except this characterkey

Can someone provide me the query for expected output ? I am using mariadb 10.6.12