Chatwoot offers two services for sending push notifications:

1. The first service sends push notifications through a relay server.

2. The second service sends push notifications directly through the Chatwoot server.

The flow of push notifications is determined by the environment variable and installation configuration details.

```
ENABLE_PUSH_RELAY_SERVER
```

Navigate to `<installation_url>/super_admin/app_config`. Check if you have added the `Firebase Project ID` and `Firebase Credentials`.

* If both `Firebase Project ID` and `Firebase Credentials` have been added, push notifications will be sent to your custom-built mobile apps.

* If neither `Firebase Project ID` nor `Firebase Credentials` have been added, and `ENABLE_PUSH_RELAY_SERVER` is true, push notifications will be sent to official mobile apps.

* If neither `Firebase Project ID` nor `Firebase Credentials` have been added, and `ENABLE_PUSH_RELAY_SERVER` is false, push notifications will not be sent to any device.

To enable push notifications on a **custom branded app**, you must configure Firebase. Detailed instructions can be found [here](https://developers.chatwoot.com/contributing-guide/mobile-app/setup-guide#push-notifications).

In summary, you need to either use custom builds for both Android and iOS apps or use the official apps for both platforms.