How to close the modal in react native

Just add this prop in Modal

onRequestClose={() => { this.visibleModal(false); } }

It will close your modal on pressing back button

<Modal animationType={"slide"}
   transparent={true}
   visible={this.state.visibleModal}
   onRequestClose={() => { this.visibleModal(false); } }
>

EDIT

Above code will work only on Android as per the document.

For both,

You can add custom button to close modal

<TouchableOpacity
    onPress={() => {
        this.setState({visibleModal: false})
    } }>
    <Image
        style={[styles.modalBackIcon]}
        source={require('../../theme/images/back-icon.png')} />
</TouchableOpacity>