How to enable CORS in Nginx

I have tried every tutorial on the internet and on serverfault regarding this. No matter what I do, CORS is not working in nginx

Here is my example.conf

server {
        root /var/www/html;
        index index.php index.html index.htm index.nginx-debian.html;
        server_name www.arcadesite.io arcadesite.io;

    location = /favicon.ico { log_not_found off; access_log off; }

location = /robots.txt { log_not_found off; access_log off; allow all; }
location ~* \.(css|gif|ico|jpeg|jpg|js|png)$ {
    expires max;
    log_not_found off;
}


    location / {
            try_files $uri $uri/ /index.php$is_args$args;
            add_header Access-Control-Allow-Origin *;

     }

    location ~ \.php$ {
            include snippets/fastcgi-php.conf;
            fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
    }

    location ~ /\.ht {
            deny all;
    }


    location ~* \.(eot|ttf|woff|woff2)$ {
    add_header Access-Control-Allow-Origin *;
    }


listen 443 ssl http2;
ssl_certificate /etc/letsencrypt/live/arcadesite.io/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/arcadesite.io/privkey.pem;
include /etc/letsencrypt/options-ssl-nginx.conf;

ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;


include rocket-nginx/default.conf;

}
server {
    if ($host = www.arcadesite.io) {
        return 301 https://$host$request_uri;
    }


if ($host = arcadesite.io) {
    return 301 https://$host$request_uri;
}


    listen 80;
    server_name www.arcadesite.io arcadesite.io;
return 404;include rocket-nginx/default.conf;}