for example, when I enter the page, I get first-level categories, such as data

data : [
    {
        id: "2",
        parentId: 1,
        name : ""
    },
    {
        id: "2",
        parentId: 1,
        name : "2"
    }
]

then query the API to the backend based on this id, such as the query to id=2, and then get the subordinate

[
    {
        id: "5",
        parentId: 2,
        name : ""
    },
    {
        id: "6",
        parentId: 2,
        name : "2"
    }
]

how to implement, how to insert the query into the parent class as his children