[Sugestão] Possível solução para a implementação

Fiz algumas alteraçoes no código da aula, ao invés de instanciar os objetos e usar uma interface, transformei os métodos em estáticos

package br.com.alura.Screenmatch;

import br.com.alura.Screenmatch.model.DadosSerie;
import br.com.alura.Screenmatch.service.ApiRequest;
import br.com.alura.Screenmatch.service.DataConverter;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ScreenmatchApplication  implements CommandLineRunner {

    public static void main(String[] args) {
        SpringApplication.run(ScreenmatchApplication.class, args);
    }


    @Override
    public void run(String... args) throws Exception {
        var API_KEY = System.getenv("API_KEY");
        var json = ApiRequest.obterDados("http://www.omdbapi.com/?t=Supernatural&apikey="+API_KEY);
        DadosSerie dados = DataConverter.getData(json,DadosSerie.class);
        System.out.println(dados);
    }
}

package br.com.alura.Screenmatch.service;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class DataConverter  {
    private static ObjectMapper mapper = new ObjectMapper();

    static public <T> T getData(String json, Class<T> classe) {
        try {
            return mapper.readValue(json,classe);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
    }
}

package br.com.alura.Screenmatch.service;

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class ApiRequest {
    public  static String obterDados(String endereco) {
        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create(endereco))
                .build();
        HttpResponse<String> response = null;
        try {
            response = client
                    .send(request, HttpResponse.BodyHandlers.ofString());
        } catch (IOException | InterruptedException e) {
            throw new RuntimeException(e);
        }

        return response.body();
    }
}