Why is the printed data an illegal operation?

Question

代码：login: function(){    wx.login({      success:function(res){        console.log(res.code)        wx.request({          url:'https://xiaoyuan.0319zp.cn/interface.php/home/index/login',          data:{ js_code:res.code},          header:{            'content-type' : 'application/json'          },          success:function(res){            console.log(res.data)          }        })      }    })  }