Android Studio Cannot find API Key - Login With Amazon

In my Android Studio project, I have got my LWA API key and saved in in the parent directory > assets folder as api_key.txt and also in my app>build>intermediates>assets folder.

Still my it cannot find the API Key. Log :

getAppInfoFromAPIKey : packageName=:<obscured>
            D  Finding API Key for :<obscured>
            I  Unable to get api key asset document: api_key.txt
           W  Unable to get API Key from Assests
         I  Attempting to parse API Key from meta data in Android manifest
         I  Attempting to parse API Key from meta data in Android manifest
           D  Begin decoding API Key for packageName=:<obscured>
         D  APIKey:<obscured>
        W  Unable to decode APIKey for pkg=com.example.test_itt_2
        E  FATAL EXCEPTION: main
                                                                                                    
java.lang.IllegalArgumentException: Invalid API Key
at com.amazon.identity.auth.device.authorization.InternalAuthManager.<init>(InternalAuthManager.java:59)
at com.amazon.identity.auth.device.authorization.InternalAuthManager.getInstance(InternalAuthManager.java:48)
at com.amazon.identity.auth.device.api.authorization.AuthorizationManager.authorize(AuthorizationManager.java:193)
at com.example.test_itt_2.WorkflowActivity$1.onClick(WorkflowActivity.java:31)
at android.view.View.performClick(View.java:7506)
at android.view.View.performClickInternal(View.java:7483)
at android.view.View.-$$Nest$mperformClickInternal(Unknown Source:0)
at android.view.View$PerformClick.run(View.java:29335)
at android.os.Handler.handleCallback(Handler.java:942)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7898)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)