As problem shown in the following picture

enter image description here

my code:

    <Modal
      visible={showModal}
      statusBarTranslucent={true}
      transparent={true}
      hardwareAccelerated={true}
      animationType={'fade'}>
      <Pressable style={styles.modal} onPress={onBackdropPress}>
      </Pressable>
    </Modal>

//styles
  modal: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: 'rgba(0, 0, 0, 0.3)',
  }

In portrait mode, the Modal already covers the full screen.