You can activate the code blocking for customers who did not meet certain criteria, e.g. they have fewer than 20 account comments or are new eBay users - they have an account of less than 30 days. Any transactions that do not meet certain conditions will have to be unlocked in the transaction register. Only then will the purchased products be sent to the customer.
In order to activate the dispatch lock, log in to the system and go to the Products / eBay / settings and configure the settings in the Blocking of codes sending to Customers.