Nothing else to replace
Just upload your favicon to your Shopify (you have an option through the theme usually).
And past the URL of the image where it written "url of your picture here" (keep the "")
<link rel="shortcut icon" href="url of your picture here" />
Can you share your store URL so that we can help ?
So, right now you have this on your website :
<link rel="shortcut icon" href="files/AE3ABF6F-D4DE-4F56-8AAC-49D70C77E6D9.jpeg" type="img_4405 ">
The link of the favicon points to : https://christiananisi.co/files/AE3ABF6F-D4DE-4F56-8AAC-49D70C77E6D9.jpeg
Which is a dead link.
You need to place the correct link to your picture (and you can also remove the type="img_4405" part)
Did you upload the favicon image in the assets folder ?
I know there is a way to fetch the image URL you've uploaded in the asset folder (but not sure to remember how, maybe someone else can help on this one)