Firebase: How to get a value from a node, which is named by an integer?

Question

I'm trying to get a value from Firebase Realtime Database. I'm pushing two values under one node (as seen in the screenshot below. The problem is that I can't query the nodes which are named 1 and 0, because there is an error here: ts_measure.val().1. Is there a way to get the values from this node? Thanks in advance!

Here is my code:

database.on("value", (ts_measures) => {
      const timestamps = [];
      ts_measures.forEach((ts_measure) => {
        timestamps.push({ timestamp: ts_measure.val().1 });
        console.log(ts_measure);
      });