How to add the chat to all posts?

Please locate the root folder of your theme. It is usually in /wp-content/themes/THEMENAME and edit single post template file. In most cases it is single.php file, but it may differ depending on theme.

Add the following code inside the main loop:

echo do_shortcode('[wise-chat mode="0" channel="Post #'.$post->ID.' channel"]');

This will open “Post #ID channel” channel as the classic chat.