clipboard.js

if(!navigator.clipboard){
    navigator.clipboard = {}

    navigator.clipboard.writeText = text => {       

        // A <span> contains the text to copy
        const span = document.createElement('span');
        span.textContent = text;
        span.style.whiteSpace = 'pre'; // Preserve consecutive spaces and newlines

        // Paint the span outside the viewport
        span.style.position = 'absolute';
        span.style.left = '-9999px';
        span.style.top = '-9999px';

        const win = window;
        const selection = win.getSelection();
        win.document.body.appendChild(span);

        const range = win.document.createRange();
        selection.removeAllRanges();
        range.selectNode(span);
        selection.addRange(range);

        let success = false;
        try {
            success = win.document.execCommand('copy');
        } catch (err) {}

        selection.removeAllRanges();
        span.remove();

        return success;
    }
}