In my Firebase Realtime Database I have a structure like this:

Now I want to implement a function that adds habits to this collection. Right now I am using the following code (with input.value being the value of an input element). However, the Firebase push method creates a random key everytime it adds a new element. I would like the keys to be numbers / index values, just like the elements in the screenshot have the keys 0 and 1. Is there a Firebase method that works like this (if so, I couldn't find it), and if not, how would I best implement this, so that the next element would be added with the key 2 and so on?

function addHabit() {
  push(reference(database, "habits"), {
    text: input.value,
    interval: "Daily",
  });
}