经过nginx代理后调用代理域名报错403

背景：因内网环境不通外网，需使用通外网机器代理到原域名：

原域名：https://cms.81t.mil.cn

代理域名： https://cms81t.junhao.mil.cn

nginx配置文件信息如下：

server {
    server_name cms81t.junhao.mil.cn;
    listen 443 ssl;
    ssl_certificate_key /etc/nginx/ssl/junhao.mil.cn.key;
    ssl_certificate /etc/nginx/ssl/junhao.mil.cn.crt;
    ssl_session_cache    shared:SSL:1m;
    ssl_session_timeout  5000m;
    ssl_prefer_server_ciphers  on;
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:HIGH:!aNULL:!MD5:!RC4:!DHE;
    client_max_body_size 100m;

    location / {
            proxy_pass https://cms.81t.mil.cn;
            proxy_http_version 1.1;
            proxy_redirect off;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
}
}

重启nginx后，验证信息如下：代理后的域名报错403

?解决方法：

?修改此行：proxy_set_header Host $proxy_host;

重启nginx后再次验证 ：