public/images/tray
there you can check the all currents icons used by the application. You can change that files if you want.ui/icon/AppIcon.tsx
this is the icon base used to automatically generate all the icons, if you are used with tsx/jsx
probably this is the easiest way to go../src/ui/components/AboutDialog/index.tsx
where you can change the copyright. If you've changed the logo already, it will automatically reflect on this page.electron-builder.json
rocket.chat/rocket/chat.rocket/rocketchat
according to what each setting means