Computer Configuration > Administrative Templates > Google Chrome > Default search provider
Both
HKLM\Software\Policies\Google\Chrome
If DefaultSearchProviderEnabled is on, then setting DefaultSearchProviderSuggestURL specifies the URL of the search engine to provide search suggestions. The URL should include the string '{searchTerms}', replaced in the query by the user's search terms. You can specify Google's search URL as: '{google:baseURL}complete/search?output=chrome&q={searchTerms}'. Example value: https://search.my.company/suggest?q={searchTerms}