Some code

System

onVanillaReady((vanilla) => {
    const themeHeader = document.getElementById('themeHeader').shadowRoot;
    const customMessageContainer = themeHeader.getElementById('customMessage');

    const path = window.location.pathname;
    var message;
    switch (path) {
    case '/':
        message = 'Welcome to the community!';
        break;
    case '/profile':
        message = 'To edit your profile, click on Edit';
        break;
    case '/discussions':
        message = 'Please dialogue responsibly.';
        break;
    default:
        '';
    }

    if (message) {
        customMessageContainer.textContent = message;
        customMessageContainer.style.display = 'block';
    }
});