Nginx中使用if指令加载多域名SSL证书报错的解决方法求助

各位大佬好，我最近碰到个Nginx配置的难题，想请教下大家：

我有两个域名 foo.com 和 bar.com，都是用Nginx来提供服务的。为了避免重复写配置代码，我打算把下面这段逻辑加到我的nginx.conf里：

[some code]

if ($host = "foo.com") {
    ssl_certificate /etc/letsencrypt/live/foo.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/foo.com/privkey.pem;
}

if ($host = "bar.com") {
    ssl_certificate /etc/letsencrypt/live/bar.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/bar.com/privkey.pem;
}

[some code there]

结果Nginx检测配置的时候直接报错了，具体错误信息如下：

• Checking nginx' configuration ...
  2023/07/18 20:10:15 [emerg] 2656#2656: "ssl_certificate" directive is not allowed here in /etc/nginx/nginx.conf:46
  nginx: configuration file /etc/nginx/nginx.conf test failed
  2023/07/18 20:10:15 [emerg] 2657#2657: "ssl_certificate" directive is not allowed here in /etc/nginx/nginx.conf:46
  nginx: configuration file /etc/nginx/nginx.conf test failed

有没有大佬知道我该怎么调整配置才能实现这个需求呀？

备注：内容来源于stack exchange，提问作者somenxavier