How to Read the data from a sub collection from firestore database in React

Question

I'm creating a Firebase project and I have a collection with a nested collection. I have tried to perform CRUD operations in the parent collection but I have no idea how to get the document data from the nested array.

Here is what my firestore database looks like:

and here is the code that I wrote for reading and creating a document in the parent child:

    const addEntry = () => {
    try {
        const docRef = firestore.addDoc(firestore.collection(db, "quiz"), {
            question: "How many sides are equal in a scalene triangle?",
            question_no: 1,
        });
        console.log("Document written with ID: ", docRef.id);
    } catch (e) {
        console.error("Error adding document: ", e);
    }
};
const getData = () => {
    firestore
        .getDocs(firestore.collection(db, "quiz"))
        .then((querySnapshot) => {
            querySnapshot.forEach((doc) => {
                console.log(`${doc.id} => ${doc.data()}`);
            });
        });
};

How can I get the data from the sub-collection or the nested collection.