On click of the link, the link is opening on a new tab on the browser and not in iframe and iframe is a blank box
<iframe name="iframenew" height="300px" width="100%" title="Iframe Example"></iframe>
<p><a href="https://alight.com" target="iframenew">AVA</a></p>
I want the link to open in the iframe itself
Are you refers to the message alight.com refused to connect.?
Some websites disable embedding iframe, you could check using X-Frame-Options
When attempting to embed an iFrame into your course, you may occasionally run into some errors such as seeing a blank white box or error notification. This is because not all websites can be embedded.
<iframe name="iframenew" height="300px" width="100%" title="Iframe Example"></iframe>
<p><a href="https://alight.com" target="iframenew">AVA</a></p>There is nothing wrong with the code, you could see below, I switch the link to Wikipedia main page, it will work find.
<iframe name="iframenew" height="300px" width="100%" title="Iframe Example"></iframe>
<p><a href="https://en.wikipedia.org/wiki/Main_Page" target="iframenew">AVA</a></p>