could be used for various cases.

the following will validate biometric auth or register a new one.

(async () => {
  try {
    // Check if WebAuthn is supported in the browser
    if (!window.PublicKeyCredential) {
      console.log("WebAuthn is not supported in this browser.");
      return;
    }

    // Create a random challenge (this would usually come from the server)
    const challenge = new Uint8Array(32);
    window.crypto.getRandomValues(challenge);

    const publicKeyCredentialCreationOptions = {
      challenge: challenge,  // Random challenge from the server
      rp: {
        name: "Example Corp",  // Name of your site/service
        id: window.location.hostname
      },
      user: {
        id: Uint8Array.from(window.crypto.getRandomValues(new Uint8Array(16))),  // User ID (must be unique per user)
        name: "[email protected]",  // Username/email for the user
        displayName: "Example User"
      },
      pubKeyCredParams: [
        {
          type: "public-key",
          alg: -7  // Algorithm, usually ECDSA with SHA-256
        }
      ],
      authenticatorSelection: {
        authenticatorAttachment: "platform",  // Use device's biometric (platform) authenticator
        userVerification: "required"
      },
      timeout: 60000,
      attestation: "direct"  // Attestation type
    };

    // Register a new passkey if none exist
    let credentials;
    try {
      credentials = await navigator.credentials.get({
        publicKey: {
          challenge: challenge,
          rpId: window.location.hostname,  // The relying party's domain (this website)
          allowCredentials: [], // Empty to allow user to choose from any available credentials
          userVerification: "required"
        }
      });
      console.log("Biometric Authentication successful!");
      console.log("Credential ID:", credentials.id);
    } catch (error) {
      console.log("No credentials found, attempting to create one.");

      // If no credentials are available, we create a new one
      const newCredential = await navigator.credentials.create({ publicKey: publicKeyCredentialCreationOptions });
      
      // Store the credential for future logins (typically, you'd send this to a server)
      console.log("New passkey created:", newCredential);
      
      // Now that we've created a passkey, attempt to use it for authentication
      credentials = await navigator.credentials.get({
        publicKey: {
          challenge: challenge,
          rpId: window.location.hostname,
          allowCredentials: [
            {
              id: newCredential.rawId,
              type: "public-key",
              transports: ["internal"]
            }
          ],
          userVerification: "required"
        }
      });
      console.log("Biometric Authentication successful after creating passkey!");
      console.log("Credential ID:", credentials.id);
    }
    
  } catch (error) {
    // Log the error if authentication or registration fails
    console.log("Error during authentication or registration:", error);
  }
})();