Computer Configuration > Administrative Templates > Google Chrome > Generative AI
Both
HKLM\Software\Policies\Google\Chrome
This policy controls Google's AI Mode integrations in the address bar and the New Tab page search box. To access this feature, Google must be set as the user's default search engine. 0/unset = The feature will be available to users. 1 = The feature will not be available to users. If the policy is unset, its behavior is determined by the GenAiDefaultSettings policy.