androidNotificationChannelId property
The ID of the media notification channel. This will default to
<YOUR_PACKAGE_NAME>.channel where <YOUR_PACKAGE_NAME> is your app's
package name. e.g. com.mycompany.myapp.channel.
If your app uses multiple notification channels, make sure each channel has a unique ID so that they don't clash. It is recommended to override the default ID.
NOTE: After a user installs and runs your app, a channel will be created with this ID and will show up in the app's settings. If you subsequently change this channel ID here, it will result in a new channel being created under the new ID leaving the old channel still visible. Therefore, if your app has already been published, you might prefer to keep using the same channel ID that you are currently using.
Implementation
final String? androidNotificationChannelId;