A tag have href and click event.

Sure but you need to have a method doing it.

You @click runs one function name then inside that function you run every step.

@click="doStuff()"

function doStuff() {
    checkPaymentForm();
        addBookingToDatabase();
        kortaSubmitForm();
}

Now I get this:

Access to XMLHttpRequest at 'https://netgreidslur.korta.is/?amount=5500&currency=ISK&merchant=8190444&terminal=52176&description=Park%20and%20fly&lang=is&checkvaluemd5=1e1a5f681a57c9d383bbbbf686934467&downloadurl=https://parkandfly.is/api/database/booking/update&refermethod=POST&refertarget=_top&reference=null&startnewpayment=y' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

But I have Cors.php like this:

public function handle($request, Closure $next)
    {
        return $next($request)
            ->header('Access-Control-Allow-Credentials', 'true')
            ->header('Access-Control-Allow-Origin', '*')
            ->header('Access-Control-Allow-Headers', 'X-Requested-With');
    }

Do you own and control "netgreidslur.korta.is"?

If so, then try laravel-cors instead of custom middleware.

If not, you'll want to make the request to your backend which itself makes the call to netgreidslur.korta.is to avoid CORS issues.

Okay, thanks!