Javascript 遍历文档时如何获取集合中文档的文档引用

我正在try 使用updateDoc方法从文档中的数组中删除数组元素，因此我需要文档引用，但我不知道如何获取它，因为它是由Firebase生成的，文档或过go 的问题没有帮助.

   const subjectRef = collection(db, "users", auth.currentUser.uid, "subjects");
const querySnapshot = await getDocs(subjectRef);

subjects.forEach(subject => {
    querySnapshot.forEach((doc) => {
      if(doc.data().Subject == subject) {
        const subject = doc.data();
        const subjectName = subject.Subject;
        const topics = subject.Topics;
        //iterates through the topics of the subjects
        globalTopicList.forEach(obj => {
          topics.forEach(async topic => {
            if(obj[1]==topic.id) {
              const temp = {
                Topic: topic.Topic,
                Days: 0,
                Rating: topic.Rating,
                id: topic.id,
              };
              await updateDoc(docRef, {
                Topics: arrayRemove(topic.id)
              });
              console.log('done');
            }
          });
        });
      }
    });
  });