With this code, you can customize the name of the pdf quote document generated when an administrator sends the quote to the customer.
Add this code in the file functions.php of your theme or child-theme, change the string ‘custom_name_’ with the string that you prefer.
The variable $quote_id is necessary to make the document unique inside the folder.
If you want to mask the number of the quotes, you can use the PHP functions like
Plugin info: YITH WooCommerce Request a Quote Premium