How to set up an Authenticator to Roblox on iPad without the passkey

Help!! Darling daughter clicked a link on Roblox and someone has hacked her account. We have gotten it back only for them to change the email and password each time we get it back. She has an iPad. Is there any scan we can do to see how they keep regaining access? I would love to just say not play anymore but I want to get back on and remove my payment for monthly premium.

Also I’m clueless as with setting up an Authenticator and I don’t remember the passkey I created 2 years ago. Roblox support is no help.

[Edited by Moderator]