This is a tiki preference located at "Look and Feel -> Miscellaneous -> Favicons"
The preference is enable by default.
Favicons are used by an operating system or browser for various tasks such as bookmarking, dock icons, quick navigation screens, web history, or any other task that the OS/Browser may do. Favicons allow custom icons that match the look and feel of the operating system to be integrated into the user experience.
realfavicongenerator.net or any other favicon generator and drop your generated favicons into themes/yourtheme/favicons/.
Some generator may also add with the icons they generate extra code (xml, js, etc). Those files are not necessary and it is advised to add only the favicons in different formats (.png, .jpg, .svg, etc).
As per Tiki19, you may need to create the directory if it does not exist.
The default Tiki favicons may be customized in any place that tiki looks for theme overrides, including perspectives, multitki etc. The default favicons can be found at themes/base_files/favicons.
Favicons must be named according to the files in themes/base_files/favicons. No other favicons will be used.
Placing favicon-16x16.png in your themes favicon directory will trigger tiki to look for the rest of the favicons in your customized folder. You must use favicon-16x16.png, but may choose not to use the remaining favicons. When favicon-16x16.png is the only file placed in your theme favicon directory, none of the default tiki icons will be displayed.
To generate all the favicons and the supporting xml & json files, visit realfavicongenerator.net. RealFaviconGenerator.net continues to update their generated files according to browser support and new standards. Tiki follows the lead of the recommendations on this website for its favicon support.