How can I add a Button to my wear OS app?

I am adding a Button to my first Wear OS application. When I follow a model from my existing Android applications, there appears to be difference due to "WearableActivity" versus "Activity". I cannot define the OnClickListener.

In my on create is this:

bottomButton = findViewById(R.id.bottomButton);
        setListener();

later in the main activity source is this

void setListener()
    {
            bottomButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) // toggle between report and graph display
            {   if (showGraph)
                    {showReport=true; showGraph=false;bottomButton.setText("show Report");}
                else
                    {showReport=false;showGraph=true;bottomButton.setText("show Graph");}



            }  // end, onClick
        }); // end, setOnClickListener
    } // end, setListener()

In both cases the button is defined in XML and found and used as follows

OkButton = (Button) findViewById(R.id.OkButton);
OkButton.setOnClickListener(this);

from How can I add a Button to my wear OS app?