App.js

const App = () => {
   return(
     <View style={styles.container}>
       <Text>Push Notifications</Text>
       <TouchableOpacity 
       activeOpacity={0.6} 
       //calling showNotifications
       onPress={ ()=> showNotifications('hello', 'message')}>
         <View style={styles.button}>
           <Text style={styles.buttonTitle}>Click me to get notification</Text>
         </View>
       </TouchableOpacity>
       <TouchableOpacity 
       activeOpacity={0.6}
       //calling handleScheduleNotifications
       onPress={ ()=> handleScheduleNotifications('Hi', 'Showed after 5 sec')}>
         <View style={styles.button}>
           <Text style={styles.buttonTitle}>Click me to get notification after 5sec.</Text>
         </View>
       </TouchableOpacity>
       <TouchableOpacity 
       activeOpacity={0.6}
       //calling handleCancel
       onPress={ ()=> handleCancel()}>
         <View style={styles.button}>
           <Text style={styles.buttonTitle}>Click me to cancel all notifications</Text>
         </View>
       </TouchableOpacity>
     </View>
   );
 };