Sometimes when doing large migrations or other activities involving large file uploads, you’ll run into an error message #413 from the web server: REQUEST ENTITY TOO LARGE.
You can attempt to fix this by changing options in your NGINX and PHP configuration files
Update the client_max_body_size in your nginx configuration files – from 25M (default) to something larger such as 100M or 250MB.
To do this you will need to ssh into your server:
Once you’re in:
service nginx restart
Update the post_max_size entry in your php.ini file – from 25M (default) to something larger such as 100M or 250MB. You can do this from the WPCD site admin screen under the PHP tab. However, since you might already be in the server, you can change it from the command line as well:
systemctl stop php7.4-fpm
systemctl start php7.4-fpm
From Key CDN: Fixing 413 Request Entity Too Large Errors