location /app-dev {
    rewrite ^/app-dev/(.*) /$1 break;
    proxy_pass http://152.136.36.251:9999;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
}

   location /请求后缀 {
    rewrite ^/app-dev/(.*) /$1 break;
    proxy_pass 想要的请求后端的url;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
}