Phone updated somehow now my authenticator is unlinked and its sending sms to an old cellphone number that was shutoff a year ago

So my iPhone updated the other night and I never use the authenticator because everything is saved on my PC. I play Heroes of The Storm and I’m on a team for Nexus Gaming Series and to log in to there website you need to log in to went to do that it sent the authenticator to my iPhone and I can’t get it. The only viable option I have is to send SMS but that goes to an old cell number I turned off because at&t had a deal buy a phone get one free if I got a new number or some bs like a year ago. I’m still able to play and stuff because I haven’t logged out but I’m worried this may become an issue where I’m locked out of my account and as I am staff for NGS as well I need to be able to log into the website to fulfill my duties. Please Help I know its Xmas eve I’m not expecting an answer tonight but soon would be great Thanks in advance.