Can the webIDE use Bangle.http function? it didn't work.

What you're missing here is that you're doing JSON.parse(data) and not JSON.parse(data.resp)

This works great though:

Bangle.http("https://worldtimeapi.org/api/ip").then(data => {
  let time = JSON.parse(data.resp).datetime.split("T")[1].split(".")[0];
  g.clear();
  g.drawString("Time: " + time, 120, 120);
}).catch(err => {
  g.clear();
  g.drawString("Error: " + err, 120, 120);
});

An in the other 7 posts you made about this - it really helps to use the remote debugging for this so you can see what's going on: https://www.espruino.com/Gadgetbridge#remote-debugging