Step 3

Note the App's state:

  constructor(props) {
    super(props);
    this.state = {
      key: "",
      location: "",
      which: "",
      code: "",
    };
  }

The state is passed to the Card components:

  render() {
    const { key, location, which, code } = this.state;
    return (
      <Container className="p-3">
        <Header />
        <Row>
          <Card title={"event.key"} value={key} />
          <Card title={"event.location"} value={location} />
          <Card title={"event.which"} value={which} />
          <Card title={"event.code"} value={code} />
        </Row>
      </Container>
    );
  }