PBE and URF gamemode...

I really wanted to know if I had missed the URF game mode, first of all. I keep reading about it being on 4/01-4/02, so I would really like to know if I would be able to participate in it. Secondly, I've had a bug with the PBE website, https://pbesignup.na.leagueoflegends.com/en/pbe-signup . Whenever it would ask me to sign into my account, but after clicking on the "I want to help!" button, after putting in my correct account details, it does not move off of the loading circle. Am I too late to help, or is something specifically wrong that I did? Thank you!