Creating a Custom Event Property for Session Landing URL

Hi everyone, I’m looking to create a custom event property that captures the session landing URL. The goal is to determine whether a session started on the homepage or not. I’d then combine this with UTM Source and Referrer to better understand if the session came from direct traffic. I’ve gone through the documentation and tried asking kapa.ai but I haven’t found a clear way to do this yet. Do you have any guidance on how to achieve this? Thanks so much