<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <!--on below line we are creating a pay view-->
    <com.fevziomurtekin.payview.Payview
        android:id="@+id/payview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:cardAnimationType="vertical"
        app:cardBgColor="@color/purple_200"
        app:cardCvErrorText="You must enter 3-digit characters"
        app:cardCvTextSize="14"
        app:cardExpiredErrorText="Your card has expired. Please enter the usage date correctly."
        app:cardFgColor="@android:color/white"
        app:cardMonthErrorText="You must enter 2-digit characters and you'll enter to number the most digit-value is '12'"
        app:cardMonthTextSize="13"
        app:cardNameHelperText="Enter to name on Your Card."
        app:cardNameTextSize="15"
        app:cardNoTextSize="14"
        app:cardNumberHelperText="Enter your 16-digit card number."
        app:cardTextColor="@color/purple_200"
        app:cardYearErrorText="You must enter 2-digit characters and you'll enter to number the most digit-value is '99'"
        app:cardYearTextSize="13" />

</RelativeLayout>

import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.fevziomurtekin.payview.Payview;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // on below line we are creating a variable
        // for our pay view and initializing it.
        Payview payview = findViewById(R.id.payview);

        // on below line we are setting pay on listener for our card.
        payview.setPayOnclickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // after clicking on pay we are displaying toast message as card added.
                Toast.makeText(MainActivity.this, "Card Added. ", Toast.LENGTH_SHORT).show();
            }
        });
    }
}