i cannot log in to my iphone

You need to recover the Apple ID and password that is causing the lock so you can sign out.

See if you can recover the ID/password.

Apple ID - How to find your Apple https://support.apple.com/en-us/HT201354 An iCloud e-mail address is an Apple ID.

Apple ID - Find https://iforgot.apple.com/appleid#!&section=appleid

Enter the Apple (iCloud) ID and click Forgot Password.

Apple ID - Manage https://support.apple.com/en-us/HT201487

Apple ID – Forgot Password https://support.apple.com/en-us/HT201487

If this is a used device, you will need to contact the previous owner to have them log out of iCloud or go to https://www.icloud.com/find/ My Phone and erase the device, then remove it from their account. If you can’t do that, the device is useless.

Turn off Activation Lock - Apple Support. https://support.apple.com/en-us/HT201441

If necessary, if you are the original owner, take the device, the original purchase receipt with the serial number, and a photo ID to the nearest Apple Store.

Genius Bar Reservation and Apple Support Options - Apple. https://whttps://getsupport.apple.com/.

or contact Apple ID Support. They will need to see the original purchase receipt/paperwork also.

Apple ID - Official Applhttps://support.apple.com/en-euro/itunes-contact

Contact Apple for help with Apple ID account security - Apple Suppohttps://support.apple.com/en-euro/itunes-contact

Get Support https://getsupport.apple.com/. Work through the screens to get ahttps://support.apple.com/en-euro/itunes-contact

Or fill out and submit iTunes Store - Contact Us - Official Apple Support https://support.apple.com/en-euro/itunes-contact The form is for iTunes, but it will get passed to the ID Support section.