After implementing firebase dependencies to show firebase-in-app-massage. It works properly but one time. Then, If I again send message its not working..
As described in the firebase in-app messaging document, it retrieves messages from the server once per day (on both iOS and Android)
To conserve power, Firebase In-App Messaging only retrieves messages from the server once per day. That can make testing difficult, so the Firebase console allows you to specify a test device that displays messages on demand.