the sequence of event loop in the javascript [duplicate]

I am new to learn javascript; I encountered a big confusion when I was learning async await.

async function async1() {
  console.log("async1 start");
  await async2();
  console.log("async1 end");  // why will this task be placed in microtask?
}
async function async2() {
  console.log("async2");
}
async1();
console.log("script end");

I don't understand why will "console.log("async1 end")" be placed in microtask? in my opinion, the "console" should be a synchronized task rather than an asynchronous task.