I’m having problems logging into my iCloud

Is it telling you to use the other phone to log into iCloud or is it wanting a verification code?

See if anything here helps.  If necessary, you can use account recovery as explained in the link at bottom of the article.

Verification code - how to get one and sign in with two-factor authentication.   *

Hello ~ What happens when you try to login? Messages?

~Katana-San~