By default, the Bookmark and Reading List icons appear at the top of the Safari sidebar, giving you one-click access to a selection of useful links. Before you can access the Shared Links sidebar, however, you must configure it in System Preferences. For the Safari sidebar to work with your Twitter feeds, you must add your Twitter account to the Internet Accounts list. To set up the Shared Links sidebar, complete the following steps:

With Twitter set up as an internet account, you can use the Shared Links feature in Safari. To do so, complete the following steps: The Internet Accounts preferences window lists the internet accounts you’ve already set up on your Mac (such as your iCloud account) on the left. On the right, it lists the internet account types that the operating system supports, such as Microsoft Exchange and LinkedIn. An explanation of what happens when you allow OS X to sign you into your Twitter account appears:

You can tweet and post photos and links to Twitter.Links from your Twitter timeline appear in Safari.Apps can work with your Twitter account (with your permission).

Your Twitter account is now configured to allow OS X/macOS to use the service. At the top of the sidebar, three tabs appear: Bookmarks, Reading List, and Shared Links. The Shared Links selection list fills with tweets from your Twitter feed.