FusionAuth offers a self-service registration system that allows users to sign up for accounts with ease, but it also opens up potential security vulnerabilities from attackers. The platform provides both basic and advanced registration options, with advanced registration supporting multi-step processes, custom validation, and JavaScript logic, known as lambdas, to enhance security and user experience. To mitigate risks such as fake email registrations and identity fraud, FusionAuth incorporates identity verification using third-party APIs like the Fideo Identity Verification API, which assesses the risk of fraud based on user-provided information. The system allows for real-time validation and feedback during registration, combining custom logic and email verification to bolster security. The setup process involves running FusionAuth on various environments, configuring it with license keys and API keys, and integrating the external identity verification service to improve the accuracy and security of user registrations. By utilizing these features, businesses can balance user convenience with robust protection against fraudulent activities, ensuring that only legitimate users gain access to their applications.