Computer Configuration > Administrative Templates > Microsoft Edge > Default search provider
Both
HKLM\Software\Policies\Microsoft\Edge
Specifies the URL to the search engine used for image search. Search requests are sent using the GET method. This policy is optional. If you don't configure it, image search isn't available. Specify Bing's Image Search URL as: '{bing:baseURL}images/detail/search?iss=sbiupload&FORM=ANCMS1#enterInsights'. Specify Google's Image Search URL as: '{google:baseURL}searchbyimage/upload'. See 'DefaultSearchProviderImageURLPostParams' (Parameters for an image URL that uses POST) policy to finish configuring image search. This policy is applied only if you enable the 'DefaultSearchProviderEnabled' (Enable the default search provider) and 'DefaultSearchProviderSearchURL' (Default search provider search URL) policies. Starting in Microsoft Edge 84, you can set this policy as a recommended policy. If the user has already set a default search provider, the default search provider configured by this recommended policy will not be added to the list of search providers the user can choose from. If this is the desired behavior, use the 'ManagedSearchEngines' (Manage Search Engines) policy. Example value: https://search.contoso.com/searchbyimage/upload