Check Permissions for the GPS Tutorial on the SSaurel's Blog :

OnCreate.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    locationTv = findViewById(R.id.location);
    // we add permissions we need to request location of the users
    permissions.add(Manifest.permission.ACCESS_FINE_LOCATION);
    permissions.add(Manifest.permission.ACCESS_COARSE_LOCATION);

    permissionsToRequest = permissionsToRequest(permissions);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (permissionsToRequest.size() > 0) {
            requestPermissions(permissionsToRequest.
                    toArray(new String[permissionsToRequest.size()]), ALL_PERMISSIONS_RESULT);
        }
    }
    
    // ...
}