1. 在Alexa Developer Console中，打开您的技能并导航到“Endpoint”选项卡。
2. 选择“Account Linking”下的选项
3. 在OAuth流程中，您可以选择使用Authorization Code Grant流程或Implicit Grant流程
4. 完成授权后，Alexa Skills Kit会存储令牌和刷新令牌
5. 您可以使用此令牌访问API外部服务，而无需在代码中存储敏感信息。

以下是代码示例：

const Alexa = require('ask-sdk-core');
const request = require('request');

const LaunchRequestHandler = {
  canHandle(handlerInput) {
    return Alexa.getRequestType(handlerInput.requestEnvelope) === 'LaunchRequest';
  },
  async handle(handlerInput) {
    const accessToken = getAccessToken(handlerInput);

    const options = {
      url: 'https://api.example.com/data',
      headers: {
        'Authorization': `Bearer ${accessToken}`
      }
    };

    return new Promise((resolve, reject) => {
      request.get(options, (error, response, body) => {
        if (error) {
          return reject(error);
        }

        const data = JSON.parse(body);
        const speechText = `Hello, your data is ${data.value}`;

        return resolve(handlerInput.responseBuilder
          .speak(speechText)
          .getResponse());
      });
    });
  },
};

function getAccessToken(handlerInput) {
  const session = handlerInput.requestEnvelope.session;
  const userAccessToken = session.user.accessToken;
  
  // check if the token is expired
  if (isTokenExpired()) {
    const refreshToken = getRefreshToken(handlerInput);
    const newAccessToken = refreshAccessToken(refreshToken);
    return newAccessToken;
  }

  return userAccessToken;
}

function isTokenExpired() {
  // check if access token is expired
}

function getRefreshToken(handlerInput) {
  // get the refresh token from a database or other secure location
}

function refreshAccessToken(refreshToken) {
  // send a request to the authorization server to get a new token

  return newAccessToken;
}

const skillBuilder = Alexa.SkillBuilders.custom();

exports.handler = skillBuilder
  .addRequestHandlers(
    LaunchRequestHandler
  )
  .lambda();