[рони]

niki,
может так?

input.onkeydown = function (event) {
        if (event.keyCode == 13) {
            //save value
        } else if (event.keyCode == 27) {
             event.stopPropagation();
            //input.blur();
            let dialog = createYesDoDialog("Добавить домен " + input.value + "?",
                function () {tryToSaveNewDomen(input)},
                function () {initDomens()});
            dialog.showModal();
        }
    };