How to fix this "Unable to publish push notification; err = Published push notification to not push-enabled channel" with ably

I'm trying to use push notifications with ably in a flutter app but I'm getting this error please help me solve it

You must enable channel rule on Ably Console to enable push notifications for a channel.

To do this

• Login to Ably console.
• Click on the application you want the channel rule for.
• Click on Settings
• Click on 'Add new rule' button next to 'Channel rules' section
• Enter channel or namespace id
• Tick 'Push notifications enabled'
• Click on 'Create channel rule' and you should be good to go

I hope that helps!