流程： 前端请求后台接口，后台重定向到https://open.weixin.qq.com/connect/oauth2/authorize?appid=wxc7290663e60b3a23&redirect_uri=http%3A%2F%2Fantare.fun%2Fweixin%2Fauth&response_type=code&scope=snsapi_userinfo&connect_redirect=1&state=STATE#wechat_redirect

之后前端会报跨域问题：

Access to XMLHttpRequest at 'https://open.weixin.qq.com/connect/oauth2/authorize?appid=wxc7290663e60b3a23&redirect_uri=http%3A%2F%2Fantare.fun%2Fweixin%2Fauth&response_type=code&scope=snsapi_userinfo&connect_redirect=1&state=STATE#wechat_redirect' (redirected from 'http://antare.fun/weixin/login') from origin 'null' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.