After more than 15 years covering everything Apple, it’s with a heavy heart we announce that we will no longer be publishing new content on iMore and the iMore forums will be closing as of November 1st, 2024.
Connect it to your computer and restore it via the computer's iTunes app. Note: I hope you made a recent backup because you will lose everything that's not native on the device. If you do not know the iCloud credentials then you will not be able to use the device after the procedure is complete.