HTML block allows you to embed HTMl codes safely without breaking the existing HTML codes. Embedding HTML code couldn't be more easier than dragging, dropping, copying and pasting the block into your Composer.
How to use HTML block
Once you have inserted the HTML block, you'll get a display that looks similar to the below:
Notice that, on the right-hand side of the above picture, there's an editor. This editor is used to enter the codes which you want to be displayed. Right now, you can add your desired code into the composer. It will gives you an instantaneous result on the composer.
The result on the composer would be like this.