function copyTextToClipboard(text) {

    // 如果支持 navigator.clipboard 时使用
    if (navigator.clipboard) {
        navigator.clipboard.writeText(text);
        return true; // 我们不理会异步，假装成功
    }

    // 当浏览器不支持 navigator.clipboard 时使用
    var textArea = document.createElement("textarea");
    textArea.value = text;

    // Avoid scrolling to bottom
    textArea.style.top = "0";
    textArea.style.left = "0";
    textArea.style.position = "fixed";

    document.body.appendChild(textArea);
    textArea.focus();
    textArea.select();

    try {
        return document.execCommand('copy');
    } catch (err) {
        return false;
    } finally {
        document.body.removeChild(textArea);
    }
}

window.navigator.clipboard.writeText(123)

Promise { <state>: "rejected", <reason>: DOMException }
<state>: "rejected"
<reason>: DOMException: Clipboard write was blocked due to lack of user activation.