pokemon.trade/app/javascript/packs/frontend/components/pages/pokemon/show.jsx

import React from 'react';
import {Link} from 'react-router-dom';

import {Pokemon} from '../../../api';

class PokemonShow extends React.Component {
  state = {
    pokemon: {},
  };

  async componentDidMount() {
    try {
      const data = await Pokemon.get(this.props.match.params.id);
      this.setState({pokemon: data.data});
    } catch (err) {
      console.log(JSON.stringify(err, null, 2));
    }
  }

  render() {
    return (
      <>
        {this.state.pokemon.id}: {this.state.pokemon.nickname}
        <p>
          <Link to={`${this.props.match.url}/404`}>404 page</Link>
        </p>
      </>
    );
  }
}

export default PokemonShow;