A IPN secret is required by CoinPayments in every merchant account. To set or find yours follow the next steps.

1. []Login to your CoinPayments account.
   []Go to your Account -> Account Settings section.
   []Under your Merchant Settings, set or get your IPN Secret.
   []Paste this value in the plugin settings.
   
2. Done.
   

To read more about CoinPayments IPN system follow the next link.
https://www.coinpayments.net/merchant-tools-ipn#:~:text=IPN%20Secret