Yea great, you linked to something that hasnt been updated in a long time, and doesnt work with Safari 13 or newer(latest version is 17.1).
This link - https://safari-extensions.apple.com/details/?id=com.el1t.uBlock-3NU33NW2M3 - For ublock for safari is dead.
Like I said, ublock is not available and hasn’t been for a long time now.
I love Firefox, it is my desktop and android go to, but fuck apples bullshit.
Look into Orion browser, it allows you to use chrome and Firefox extensions on iOS, it does mean no easy bookmark or tab sharing, but small price to pay to be able to use the net again properly.