i changed my phone number some time ago, i changed it for new phone inside my apple profile.
Now when i try to activate keychain, the activation proccess send the verification code to the other phone.
What can i do ¿
You can only change the number once you are successfully in the Keychain. Get help using iCloud Keychain - Apple Support
In your case, if you cannot receive the verification code and you do not have another device already logged into iCloud Keychain that you can approve from, then you will need to choose the option that says forgot code. This will allow you to reset the keychain.
keychain activation send verification number to other phone
