Wife’s iphone

She needs to start here:--> If you forgot your Apple ID password - Apple Support

and/or here:--> If you’ve forgotten the answers to your Apple ID security questions – Apple Support

If she gets no help, she should contact Apple Support using this link:--> Contact Apple for help with Apple ID account security - Apple Support

Regards

Giulio

Hopefully it’s her password (and not some stranger’s like a previous owner).

If you forgot your Apple ID password - Apple Support