if you want to add twitter feed in your website without using any secrate key or any other access then you can use below code. it is very simple and easy to use. you can see latest tweets of that user.

Code :

<a class="twitter-timeline" href="https://twitter.com/TWITTER_USERNAME">Tweets by User</a> 
<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

Output :