Gradle's Screenshot is attached Android Studio in not suggesting the keyword FirebaseRecyclerAdapter. When I tried to type it manually then it shows error. How can I solve this issue?
You are trying to use FirebaseRecyclerAdapter which is apart of the Firebase-UI library but you haven't added it's dependency at all. To solve this, please add the following dependecy in your build.gradle file:
implementation 'com.firebaseui:firebase-ui-database:4.3.1'