New iCloud account and verification code

Hello,

We bought a new iPad for our child and are trying to get it set up. We have created the iCloud account which has our (adult’s) account/mobile number linked to it. We then get a message for a verification code to activate our child’s iCloud account, however, we are unable to log in to the account we created in order to access the code. We get stuck at this stage and are unsure how to move past it. Any advice?

If we try to reset the password for our child’s account then it resets the password for the parent’s account, and locks the child’s account and we then get stuck in this endless loop. Any suggestions or ideas would be appreciated. Thank you!