Run Functional Tests using a Headless Browser - Couldn’t pass with official solution

I’ve tried everything and even the official answer after being stuck for more than two days, but I still can’t pass the test. Is anyone else having this problem?

    test('Submit the surname "Colombo" in the HTML form', function (done) {
      browser.fill('surname', 'Colombo').pressButton('submit', function () {
        browser.assert.success();
        browser.assert.text('span#name', 'Cristoforo');
        browser.assert.text('span#surname', 'Colombo');
        browser.assert.elements('span#dates', 1);
        done();
      });
    });

A link to the thing you’re working on and on explanation on where you got the ‘official’ solution would be extremely helpful. Thanks

That isn’t the correct syntax. Look at the example code, there is a promise with a .then() on it.