Upload a favicon (can be png file) in the Project -> Assets page(more info on this in our knowledge base
Copy the url that is generated for this asset (or use a self-hosted icon)
Go to the project Settings and scroll down to "Website settings"
Paste the code below in the 'Analytics code' (add it if there is other code in there). This make the favicon visible in all your Airstrip pages. What it does "technically" is replacing our default (empty) favicon with your uploaded variant
replace the two favicon.ico 's with your copied asset url
document.querySelector("link[rel='shortcut icon']").href = "favicon.ico";
document.querySelector("link[rel*='icon']").href = "favicon.ico";