Computer Configuration > Administrative Templates > Microsoft Edge - Default Settings (users can override) > Default search provider
Both
HKLM\Software\Policies\Microsoft\Edge\Recommended
You can configure the new tab page search box to use "Search box (Recommended)" or "Address bar" to search on new tabs. This policy only works if you set the search engine to a value other than Bing by setting the following two policies: 'DefaultSearchProviderEnabled' (Enable the default search provider) and 'DefaultSearchProviderSearchURL' (Default search provider search URL). If you disable or don't configure this policy and: - If the address bar default search engine is Bing, the new tab page uses the search box to search on new tabs. - If the address bar default search engine is not Bing, users are offered an additional choice (use "Address bar") when searching on new tabs. If you enable this policy and set it to: - "Search box (Recommended)" ('bing'), the new tab page uses the search box to search on new tabs. - "Address bar" ('redirect'), the new tab page search box uses the address bar to search on new tabs. Policy options mapping: * bing (bing) = Search box (Recommended) * redirect (redirect) = Address bar Use the preceding information when configuring this policy. Example value: bing