Why is my subscription link greyed out on Calendar app?

I had wanted to add the dates of f1 races however, when I go to the website to press the add button its greyed out, I’m unsure if this is a issue with the app, or the fact that I’m not using safari I have so far tried jut pressing enter, erasing and re entering a singular character and copying the link to past it in manually and none of them work however it seamlessly worked on my phone (its an android btw) this is the link that I’ve been trying to use: webcal://ics.ecal.com/ecal-sub/67fe46555ec27500081a598f/Formula%201.ics (UPDATE: I have scrolled down and found out there’s a subscribe button below sorry for the confusion or inconvenience idk which one it is)