Wit, undefined .then

gistfile1.js

Index.js (custom action)
-------------------------
activate_schedule({sessionId, context, entities}) {
    return new Promise(function(resolve, reject) {
      LevelUp.set_activation_state(sessions[sessionId].fbid, true)
        .then(user_schedule => {
          console.log(user_schedule);
          // if(user_schedule.schedule_on){
          //   context.schedule_active= true;
          //   delete context.schedule_inactive;
          // }else {
          //   delete context.schedule_active;
          //   context.schedule_inactive = true;
          // }
          return resolve(context);
        }
        );
    });


#LevelUp.js
-----------

LevelUp.prototype.get_user = function (fbid) {
  return fetch(config.LUP_API_ENDPOINT + '/users?fb_id=' + fbid, {
    method: 'GET',
    headers: {
                'Content-Type'  : 'application/json',
                'Accept'        : 'application/json',
                'Authorization' : 'Token token=' + config.LUP_API_TOKEN
              }
  })
  .then(rsp => rsp.json())
  .then(json => {
    if (json.error && json.error.message) {
      throw new Error(json.error.message);
    }
    return json;
  });
};

LevelUp.prototype.set_activation_state = function (fbid, state) {

  this.get_user(fbid)
    .then(user_profile => {
      const body = JSON.stringify({schedule:{schedule_on: state}});
      return fetch(config.LUP_API_ENDPOINT + '/schedules/' + user_profile.user.schedule.id, {
        method: 'PUT',
        headers: {
                    'Content-Type'  : 'application/json',
                    'Accept'        : 'application/json',
                    'Authorization' : 'Token token=' + config.LUP_API_TOKEN
                  },
        body
      })
      .then(rsp => rsp.json())
      .then(json => {
        if (json.error && json.error.message) {
          throw new Error(json.error.message);
        }
        console.log('set_activation_state', json);
        return json;
      });
    });
};