# Extension Modules

Attaches extensions (JS/CSS modules, userscripts, MV3 Chrome extensions) to the app.

**Where:** the **Extension modules** card in the [Edit Common Config](/guide/app-actions/edit-common-config/) editor.

## Options

- **Enable** — turn extensions on for this app (`extensionEnabled`).
- **Selected modules** — choose which installed modules run in this app (`extensionModuleIds`).
- **FAB icon** — the floating-button icon for the extension panel (`extensionFabIcon`).

## Notes

- Manage and create extensions in [Extension Modules](/guide/more-features/extension-modules).
- To author extensions, see [Extension Authoring](/extensions/).