function the_fetch3(){ setTimeout(the_fetch2,3000);}
function the_fetch3() {
  setTimeout(the_fetch2, 3000);
}

async function myDisplay() {
  let myPromise = new Promise(function(resolve) {
    setTimeout(function() {
      the_fetch3();
      resolve(alert('affichage pret'));
    }, 3000);
  });
  document.getElementById("demo").innerHTML = await myPromise;
}

myDisplay();