Stripe Payment Gateway
Stripe is a popular payment gateway that supports a wide range of payment methods, including credit and debit cards. Is certified to the highest level of PCI compliance, and offers a suite of security features like two-factor authentication, fraud detection, and tokenization.

Secret Key
It's a security credential that is used to authenticate requests made to the Stripe API. When ePRINTit SaaS set up a Stripe account, they were provided with a pair of API keys: a publishable key and a secret key.
The secret key is a private credential that should never be shared publicly, as it provides full access to the merchant's Stripe account, including the ability to create charges, refunds, and perform other sensitive operations. The secret key is used to authenticate requests made to the Stripe API from the server side of an application, such as a backend or middleware.
Webhook URL
While generating credentials for the Stripe payment gateway, a webhook URL will be generated. Users have to put that webhook URL here.