nginx-cors.conf

location /api {
   proxy_pass http://localhost:12306.cn

    add_header 'Access-Control-Allow-Origin' '*' always;

    if ($request_method = 'OPTIONS') {
        add_header 'Access-Control-Allow-Origin' '*' always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, PATCH, OPTIONS, HEAD';
        add_header 'Access-Control-Allow-Headers' 'Authorization, X-Requested-With, Content-Type';
        return 204;
     }
}