VUE+axio登录功能跨域请求验证码失败

请求验证码方法：

code() {
  axios({
    url: baseUrl,
    responseType:'arraybuffer',
    codeImg:true,
  }).then(res => {
  this.codeImg = 'data:image/png;base64,' + btoa(new Uint8Array(res).reduce((data, byte) => data + String.fromCharCode(byte), ''));
  }).catch(res => {
  })
}