hacked

Whilst I was on my iphone home page a notification popped up (it was the same style of message that pops up when iphone tells u it needs to update ur phone and asks u to confirm or do it later) the notification said ‘you r phone has been hacked and go into settings to resolve it’ it said something else as well but the message only popped up for a quick second so i couldn’t read it properly what do I do and is my iphone really hacked