I have a server with 2vcores and 7go of ram with Nginx version 1.18. When I want to test the robustness of my server with a heavy HTTP load of about 300 requests per second I get 429 errors after a few seconds.
I know that the 429 error means that a user has made too many requests and it's because of rate limiting.  In the doc of thelimit_rate directive  it says that if the value is 0 then the rate limiting feature is disabled.
I also tried this articlefrom the Nginx blog but I can't solve my problem.
Here is my Nginx configuration at the moment.
The configuration of the file /etc/nginx/nginx.conf is the default
server {
    listen 80;
    listen [::]:80;
    server_name _;
    root /var/www/laravel-rsync/public;
 
    add_header X-Frame-Options "SAMEORIGIN";
    add_header X-Content-Type-Options "nosniff";
 
    index index.php;
 
    charset utf-8;
    
    limit_rate 0;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }
 
    location = /favicon.ico { access_log off; log_not_found off; }
    location = /robots.txt  { access_log off; log_not_found off; }
 
    error_page 404 /index.php;
 
    location ~ \.php$ {
        fastcgi_pass unix:/var/run/php/php8.1-fpm.sock;
        fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
        include fastcgi_params;
    }
 
    location ~ /\.(?!well-known).* {
        deny all;
    }
}

Answer
The answer was that Laravel throttle by default all the /api route. So just comment the throttle and that will be good.