Don't see any way for me to add it, since it's not listed among the downloadable extensions (you have them for Chrome, Firefox, Opera, Safari, but not IE or Edge)
1Password Version: Not ProvidedExtension Version: Not ProvidedOS Version: Not ProvidedSync Type: Not ProvidedReferrer: kb-search:edge browser, kb:install-browser-extension
1Password for Windows modern (the "Windows 10 beta" referred to in this forum's title) doesn't have a browser extension, as Windows 10 "sandboxing" currently prevents that kind of inter-app cooperation.
I believe a future version of Edge may give us the ability to improve things a bit, but I don't know the details of what might eventually become possible.
Note: If you're asking about 1Password 4 for Windows, you might want to repost this question in the stable-version forum or the beta-version forum for that product. Thanks, @sthiemann!