You can set how many Invoices will be created by setting up the Maximum # of Invoice Created. If you want an unlimited number of Invoice creations you can input 0 as the maximum number of Invoices created. 

You can also choose how you want to limit your Multiple Payment Link, it could be every time an invoice is paid or every time an invoice is created. If your Multiple Payment Link reaches the limit, you are no longer able to create a new Invoice.