How to add favicon without using a plugin
Find a image you want to use like a favicon and use this website to make it favicon.ico
https://favicon.io/favicon-converter/
Download your favicon.ico and upload it in your root folder
then go
AdminCP >> Templates & Style >> Templates >> your theme templates >> Ungrouped Templates >> headerinclude
and add at beginning of headerinclude template
<link rel="Shortcut icon" href="{$mybb->settings['bburl']}/favicon.ico" />
hard-refresh the page a couple of times.
Find a image you want to use like a favicon and use this website to make it favicon.ico
https://favicon.io/favicon-converter/
Download your favicon.ico and upload it in your root folder
then go
AdminCP >> Templates & Style >> Templates >> your theme templates >> Ungrouped Templates >> headerinclude
and add at beginning of headerinclude template
<link rel="Shortcut icon" href="{$mybb->settings['bburl']}/favicon.ico" />
hard-refresh the page a couple of times.