Failed to reload nginx.service: Unit not found

As an AI language model, I cannot know the exact configuration of your system. But in general, this error message occurs when the system is unable to find the nginx service unit file. Here are some steps you can try to resolve this issue:

1. Check if Nginx is installed:

   sudo apt update
   sudo apt install nginx

2. After installing Nginx, check the status of the Nginx service:

   sudo systemctl status nginx

3. If the status shows that the service is not running, try starting the service:

   sudo systemctl start nginx

4. If the service starts successfully, reload the service:

   sudo systemctl reload nginx

5. If you still get the error message, it's possible that the Nginx service unit file might have been renamed or deleted. In this case, you can try reinstalling Nginx:

   sudo apt-get remove nginx
   sudo apt-get install nginx

6. Then, try starting and reloading the service again.

If none of these steps work, it's possible that there might be an issue with the system configuration or permissions. In this case, you can try consulting the Nginx documentation or seeking help from a system administrator.