Click "Customize this page" at the bottom of the page, then click the "plus" to create a new widget. From the available options, select "Embeddable Content", then click the "Add" option for "Twitter Embed Code":

From here, follow the instructions in the window for generating the embed code from Twitter.

Here are the steps for generating the embed code:
- Login to Twitter(link is external).
- Visit the Twitter publish page(link is external). Click into the "What would you like to embed?" field to see the available options.
- Note: The "A Tweet" (single tweet) option is not supported here. It is also not possible to embed hashtag search timelines.
- Determine the URL of the profile or collection you want to embed and paste it into the "What would you like to embed?" field. Alternatively, from "browse your options below", you can select the "Embedded Grid" or "Embedded Timeline" options and follow those instructions.
- Copy the code that Twitter provides and paste it into the Twitter Embed Code text box below. (Ignore Twitter's "set customization options", as those are not supported here.)
- Click the Update Preview button and you should see the Twitter timeline rendered. If things look good click the Save button at the very bottom of this window.
Note: If you are embedding tweets by a Twitter account that you own, please make sure that you are following Twitter accessibility best practices(link is external) with regard to the images that you tweet.
When you're ready, click Save to save the individual widget settings, then click Save at the bottom of the page to save the overall changes to the page.