adding favicon

I am using a liquorice child theme, and want to add a favicon. I already have my favicon.ico uploaded into the liquorice-child directory, but now I’m not sure how to activate it. I looked at a few forums, and did what they said but I couldn’t get anything to work. The frustrating thing is that I have done it before but can’t remember for the life of me how I did it. I have a sunset picture there right now and want to change it.
The site is thehealthycollective.com