The phone number must be verified in the first step when creating an account. The email address can be verified at a later stage, but if an activation or offer requires a verified email address, this must be done before participating. The system will automatically ask you to do this.
The reason why we require both phone number and email address verified is that we want to make sure that all our users end up in the right place with the right information! We ensure through the verification that all information reaches you. At the same time, we avoid cheating and abuse of our platform.