Markdown is not converting into HTML

I have written few posts in markdown format but jekyll is not rendering into html. It is all copying the same content as be input.

For example:
**This is bold**

Same is the output

Did you put the YAML block at the top of the file? Two lines of three dashes each is sufficient, although you can put metadata and variable definitions in between. It looks like this:

---
title: My post
author: That Would Be Me
---
(Content goes here. You can use {{ page.title }}, for example, to put the title in your post.)
1 Like

Yes, I have added those 3 dashes.

the filename of this post ends in .md right?

do you have html in that file also? you have to be careful when using markdown and html in the same file - it works but there is a trick you have to do.

But how to add a class in markdown?

https://kramdown.gettalong.org/quickref.html

in another post someone gave you an answer, maybe in that example there was a space missing?