Hey Sarah,
You will need access to a web server to the host the Twitter URL that you are trying to embed. In your web server if you create a basic html file that is listed in the code that I shared above it will generate a URL to the HTML File. That HTML file can then be embedded in a Rich Text Widget in the Ops Dashboard. If you don't have a web server and try to paste the Twitter embedded directly into the Rich Text Widget you will only see a hyperlink.
Ultimately below is what the HTML code should look like in you Rich Text Widget after an HTML page has been generated on your web server. I am not a programmer so it took a couple attempts to understand the process.
Twitter Updates AZ Fires
<div>
<p><iframe frameborder="0" height="500" src="https://gisweb.azdema.gov/NWSFeeds/AZFire.html" width="100%"></iframe></p>
</div>
Let me know if you still need help.
-Eric