pwa manual trigger install

window.addEventListener('beforeinstallprompt', e => {
    if (window.matchMedia('(display-mode: standalone)').matches) {
        // don't display install banner when installed
        return e.preventDefault();
    } else {
        const btn = document.querySelector('#install')
        btn.hidden = false;
        btn.onclick = _ => e.prompt();
        return e.preventDefault();
    }
});