Using OIDC and Oauth2 in openapi 3

I hope someone can help me. I have been looking at lots of forums and have not been able to find any answers.

I am hoping to use OpenAPI 3 and OIDC to get access token.

I am generating a Java client using codegen cli - java -jar swagger-codegen-cli-3.0.8.jar generate -l java ........

In my yaml I have

  securitySchemes:
    OpenID:
      type: openIdConnect
      openIdConnectUrl: https://localhost:9643/oidc/endpoint/jazzop/.well-known/openid-configuration
    OAuth2:
      type: oauth2
      flows:
        implicit:
          authorizationUrl: https://localhost:9643/oidc/endpoint/jazzop/authorize
          scopes:
            read: Grants read access
            write: Grants write access
            admin: Grants access to admin operations

The generated ApiClient.java contains only

   public ApiClient() {
        httpClient = new OkHttpClient();


        verifyingSsl = true;

        json = new JSON();

        // Set default User-Agent.
        setUserAgent("Swagger-Codegen/1.0.0/java");

        // Setup authentications (key: authentication name, value: authentication).
        authentications = new HashMap<String, Authentication>();
        authentications.put("OAuth2", new OAuth());
        // Prevent the authentications from being modified.
        authentications = Collections.unmodifiableMap(authentications);
    }

There is no mention of OpenID. Searching through the generated client, I cannot find any reference to "https://localhost:9643...." anywhere. So even oauth2 "authorization" endpoint is not accessed.

Various forums suggest that oauth2 and oidc happens automagically, but code generated suggests otherwise.

Can someone point me somewhere with more concrete examples of how it works.

Many thanks