Hey there,

I am really sorry for the delay of this reply as it is a weekend for us here.

Unfortunately currently that was not possible to add HTML in blog description from backend.

But you can try modify this file -> JoomlaFolder/components/com_easyblog/themes/wireframe/toolbar/default.php

Under this line of code :

<div class="eb-brand-bio"><?php echo JText::_($desc);?></div>

You can change this <?php echo JText::_($desc);?> this code to your HTML code.

Once you change already, you can override this file into your JoomlaFolder/templates/YourCurrentTemplate/html/com_easyblog/toolbar/default.php , those new folder/file you have to manually create it.