Make API calls using retrofit- built complete using kotlin
implementation "com.squareup.retrofit2:retrofit:2.0.0"
implementation "io.reactivex.rxjava2:rxjava:2.1.0"
implementation "com.squareup.retrofit2:adapter-rxjava2:2.3.0"
implementation 'io.reactivex.rxjava2:rxandroid:2.0.2'
implementation "com.squareup.okhttp3:logging-interceptor:3.8.0"
implementation "com.squareup.retrofit2:converter-gson:$rootProject.gsonLibraryVersion"
Also don't forget to add INTERNET permission to Manifest file without is you cannot fetch data from internet
<uses-permission android:name="android.permission.INTERNET"/>
Now <sync your project again.
Just replace API_KEY in MainActivity class with your key. To get the API_KEY for fetching data, please visit below link, it is free just enter your email and verify your apikey from mail you receive http://www.omdbapi.com/apikey.aspx