您可能使用了$ certbot --nginx命令，并编辑了nginx配置文件来查找证书：

server{
    server_name [your_domain];

    location /static {
        ...
    }

    location / {
        ...
    }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/[...]; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/[...]; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/[...]; # managed by Certbot

}

server{
    if ($host = [your_domain]) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    server_name [your_domain];
    listen 80;
    return 404; # managed by Certbot

}

$ certbot delete不会将其更改回来，因此您必须删除与证书相关的部分，并将server_name更改为您的IP地址，因此它看起来像：

server{
    server_name [your ip];

    location /static {
        ...
    }

    location / {
        ...
    }

}

注解或删除这些行

listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/[...]; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/[...]; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/[...]; # managed by Certbot

在/etc/nginx/sites-available中的所有可用文件中