Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
Ensure that queries in Bing web search are done with SafeSearch set to the value specified. Users can't change this setting. If you configure this policy to 'BingSafeSearchNoRestrictionsMode', SafeSearch in Bing search falls back to the bing.com value. If you configure this policy to 'BingSafeSearchModerateMode', the moderate setting is used in SafeSearch. The moderate setting filters adult videos and images but not text from search results. If you configure this policy to 'BingSafeSearchStrictMode', the strict setting in SafeSearch is used. The strict setting filters adult text, images, and videos. If you disable this policy or don't configure it, SafeSearch in Bing search isn't enforced, and users can set the value they want on bing.com. Policy options mapping: * BingSafeSearchNoRestrictionsMode (0) = Don't configure search restrictions in Bing * BingSafeSearchModerateMode (1) = Configure moderate search restrictions in Bing * BingSafeSearchStrictMode (2) = Configure strict search restrictions in Bing Use the preceding information when configuring this policy.