how data store in key value pair in firebase realtime database

How to store the data in this format in firebase's real-time database.

cart
 |
 |---jywzArtx9wwdg2Vdg4JfH8qBoy1  <--[uid]
        |
        |---0 <--[index of Array]
        |   | productName: "xyz"
        |   | productPrice: 125.25
        |---1
        |   | productName: "ABC"
        |   | productPrice: 33.25
        .   .
 

This is code:

function handleAddCartItemSave() {
    const uid = selectorLogin.uid;
    const cartRef = ref(database, 'cart/');
    const newCartRef = push(cartRef);
    console.log("New CartRef : ", newCartRef);
    set(newCartRef, {
        selectorCart,
        uid,
    })
    .then(() => {
        console.log("saved");
    })
    .catch((error) => {
        console.log(error);
    })
}

I'm trying to store data, but only store the uid. selectorCart is not stored in firebase realtime database. Please suggest to me what is the mistake and correct me.