I can’t log in with my Apple ID

You are sign in here .  .  .  with your Apple ID & Password.

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.

You can’t merge multiple Apple ID accounts.

What happens when you use the same Apple ID that you use to sign in here?

See -> If you can't connect or sign in to iCloud

If you can't connect or sign in to iCloud - Apple Support

The verification code isn't correct?

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.   *

Where are you trying to log in? What happens when you try to log in? Error message(s)? More information would help.