How to use the @octokit/request.request.defaults function in @octokit/request

this.apiUrl = options.apiUrl || 'https://api.github.com';
    this.proxyKey = options.proxyKey;

    if (options.octokitAPIs === undefined) {
      this.octokit = new Octokit({ baseUrl: options.apiUrl });
      const defaults: { [key: string]: string | object } = {
        baseUrl: this.apiUrl,
        headers: {
          'user-agent': `release-please/${
            require('../../package.json').version
          }`,
          // some proxies do not require the token prefix.
          Authorization: `${this.proxyKey ? '' : 'token '}${this.token}`,
        },
      };
      this.request = request.defaults(defaults);
      this.graphql = graphql;
    } else {
      // for the benefit of probot applications, we allow a configured instance
      // of octokit to be passed in as a parameter.
      probotMode = true;
      this.octokit = options.octokitAPIs.octokit;
      this.request = options.octokitAPIs.request;
      this.graphql = options.octokitAPIs.graphql;
    }
  }

requestDefaults.headers["user-agent"] = [
            options.userAgent,
            `octokit-core.js/${VERSION} ${getUserAgent()}`,
        ]
            .filter(Boolean)
            .join(" ");
        if (options.baseUrl) {
            requestDefaults.baseUrl = options.baseUrl;
        }
        if (options.previews) {
            requestDefaults.mediaType.previews = options.previews;
        }
        if (options.timeZone) {
            requestDefaults.headers["time-zone"] = options.timeZone;
        }
        this.request = request.defaults(requestDefaults);
        this.graphql = withCustomRequest(this.request).defaults({
            ...requestDefaults,
            baseUrl: requestDefaults.baseUrl.replace(/\/api\/v3$/, "/api"),
        });
        this.log = Object.assign({
            debug: () => { },
            info: () => { },
            warn: console.warn.bind(console),
            error: console.error.bind(console),
        }, options.log);
        this.hook = hook;
        // (1) If neither `options.authStrategy` nor `options.auth` are set, the `octokit` instance
        //     is unauthenticated. The `this.auth()` method is a no-op and no request hook is registred.
        // (2) If only `options.auth` is set, use the default token authentication strategy.
        // (3) If `options.authStrategy` is set then use it and pass in `options.auth`. Always pass own request as many strategies accept a custom request instance.
        // TODO: type `options.auth` based on `options.authStrategy`.

requestDefaults.headers["user-agent"] = [
            options.userAgent,
            `octokit-core.js/${VERSION} ${getUserAgent()}`,
        ]
            .filter(Boolean)
            .join(" ");
        if (options.baseUrl) {
            requestDefaults.baseUrl = options.baseUrl;
        }
        if (options.previews) {
            requestDefaults.mediaType.previews = options.previews;
        }
        if (options.timeZone) {
            requestDefaults.headers["time-zone"] = options.timeZone;
        }
        this.request = request.defaults(requestDefaults);
        this.graphql = withCustomRequest(this.request).defaults({
            ...requestDefaults,
            baseUrl: requestDefaults.baseUrl.replace(/\/api\/v3$/, "/api"),
        });
        this.log = Object.assign({
            debug: () => { },
            info: () => { },
            warn: console.warn.bind(console),
            error: console.error.bind(console),
        }, options.log);
        this.hook = hook;
        // (1) If neither `options.authStrategy` nor `options.auth` are set, the `octokit` instance
        //     is unauthenticated. The `this.auth()` method is a no-op and no request hook is registred.
        // (2) If only `options.auth` is set, use the default token authentication strategy.
        // (3) If `options.authStrategy` is set then use it and pass in `options.auth`. Always pass own request as many strategies accept a custom request instance.
        // TODO: type `options.auth` based on `options.authStrategy`.

function Octokit(plugins, options) {
  options = options || {};
  const hook = new Hook.Collection();
  const log = Object.assign(
    {
      debug: () => {},
      info: () => {},
      warn: console.warn,
      error: console.error
    },
    options && options.log
  );
  const api = {
    hook,
    log,
    request: request.defaults(parseClientOptions(options, log, hook))
  };

  plugins.forEach(pluginFunction => pluginFunction(api, options));

  return api;
}

function init() {
	logger.info("Initializing GitHub App ...");

	var pem = fs.readFileSync(configuration.getOption("app-pemfile"));
	
	auth = createAppAuth({
		  id: configuration.getOption('app-appid'),
		  privateKey: pem,
		  clientId: configuration.getOption('app-clientid'),
		  clientSecret: configuration.getOption('app-clientsecret'),
		  request: request.defaults({
			  baseUrl: configuration.getOption('baseurl')
		  })  
	});
	
	logger.debug(auth);
}

constructor({ id, privateKey, baseUrl, cache }) {
        const state = {
            id,
            privateKey,
            request: baseUrl ? request.defaults({ baseUrl }) : request,
            cache: cache || getCache()
        };
        this.getSignedJsonWebToken = getSignedJsonWebToken.bind(null, state);
        this.getInstallationAccessToken = getInstallationAccessToken.bind(null, state);
    }
}