In a Pega Constellation application, I need to implement the following functionality for collecting account numbers from users. Could anyone please advise on the best way to design this?

•     User must enter a minimum of 1 account number, with a maximum of 50 account numbers.
•     Plus+ icon appears below the account list. Clicking the icon adds another account
•     User has the option to remove
•     For each account, the user must enter the following
•     Text input box that supports the format (16n)
•     Error message if empty or misformatted: "16-digit account number is required"