What to do with my Cardano wallet after network update ??

Hi, I have a problem with my Cardano Yoroi wallet and I cannot access my funds. When he tries to log in, he shows the message "Yoroi is in maintenance mode". From what I can remember, Ada went through a Shelley hard fork, but I don't know what to do to get her Ada back. Is there anyone who knows about it and will explain in a simple way what needs to be done ?? Thank you in advance.