where do I get verification code for apple ID?

With AppleID 2 factor authentication, the 6 digit code will be sent as an iCloud notification to all your trusted devices.

As backup in the event you don’t have access to a trusted device, you can have a code sent to your registered SMS text or voice telephone number.

Get a verification code and sign in with two-factor authentication - Apple Support

Hello!

You should be getting the verification code on one of your trust apple devices. Check out the links below for more details about the verification code and two factor authentication:

Get a verification code and sign in with two-factor authentication: https://support.apple.com/en-us/HT204974

Two-factor authentication for Apple ID: https://support.apple.com/en-us/HT204915

Let me know if this helps!