If you ever find yourself needing to display a small icon for a 3rd party URL but don’t want to have to crawl the site to pull out the favicon URL then you can make use of a Google CDN:

https://s2.googleusercontent.com/s2/favicons?domain_url=https://www.bbc.co.uk/

Example:

You can even provide any page, not just the root URL.

e.g. https://s2.googleusercontent.com/s2/favicons?domain_url=https://www.bbc.co.uk/news/newsbeat-54838856: