here is quick way that i used to add a twitter follow button.
first open this link in the web browser https://publish.twitter.com
second select a handle lik @TwitterDev
alternatively you can also pick Twitter Button from the Browse your option below
third select Follow Button from the Modal
now you can copy the generated code or do additional work by click on the customization link
here is the generated code from my twitter account
<a
href="https://twitter.com/Danhdeng" class="twitter-follow-button"
data-show-count="false">Follow @Danhdeng</a><script async
src="//platform.twitter.com/widgets.js"
charset="utf-8"></script> 
