For the proper functionality of desktop apps your site must have Nexus app installed.
Change the following values to your own in src/index.js file:
const BASE_URL = 'https://una.io/';
const TEMPLATE = 'protean';
const TITLE = 'UNA.IO Messenger';
const TRAY_TOOLTIP = 'UNA.IO Messenger (double-click - hide, click - focus)';Make 1024x1024 icon and place it instead of res/AppIcon.png.
To generate AppIcon.icns you can use use IconGenerator app.
To generate AppIcon.ico use any tool to resize it to 150x150 and convert to .ico format, for example GIMP.
Tray icons are needed for Windows only and can created using any suitable image editor.
Windows build must be made on Windows - run package-win.bat.
Mac build must be made on Mac only - run package-mac.sh.