ISC2 CPE (Continuing Professional Education) credits are a system used to track and measure the ongoing professional development and education of its certified members.

If you have a VIP or VIP+ subscription on HTB Labs, you can get the credits on a monthly basis by playing Machines, Challenges, ProLabs, and Endgames.

You can learn more about that here:

An ISC2 ID, often referred to as your "Member ID" or "Certification ID," typically consists of a series of numbers unique to each certified member of ISC2. The exact format of the ID may vary, but it typically follows a pattern like the following:

123456

Your ISC2 ID is typically provided when you first become certified or join (ISC)² as a member. It's a unique identifier used for various purposes, including accessing the (ISC)² member portal, verifying your certification status, and participating in (ISC)² activities and events.

To add this Member ID to your account you need to navigate to your Account Settings and click on Manage HTB Account:

This will redirect you to your HTB Account page where you can find the User Settings tab, you can fill in the ISC2 ID field with your ID: