Good SEO practice entails having clean & working code on the backend of your sites.
Once the code has been converted, simply copy and paste the desired code type to the backend of your site.
What is HTML?
HyperText Markup Language (HTML) is the standard markup language for creating web pages and web applications. (source)
What is PHP?
Hypertext Preprocessor (PHP) is a server-side scripting language designed primarily for web development but is also used as a general-purpose programming language. (source)
What is ASP?
ASP.NET (ASP) is an open-source server-side web application framework designed for web development to produce dynamic web pages. (source)
What is JS?