You need to have the latest version of Pocket / Evernote app installed, as from Yosemite, El Capitan it provides a sharing extension, which is recommended to use by Apple.
Download Pocket from the Mac App Store
Download Evernote from the Mac App Store
Pocket / Evernote needs to be enabled at Newsflow / Preferences / Sharing and please make sure that the sharing is also enabled at System Preferences / Extensions / Share Menu list.
In case if you still don't see the sharing among your sharing options, please disable it at Share Menu list, restart your Mac and re-enable it.