How do I set up my son's iPhone with a smashed screen and locked iCloud using a new Apple ID?

setting up my sons phone, he doesnt have access to his other as the screen is smashed, set up a new apple id and i provided my phone number to send the code to now his icloud is locked and we can’t access it, yet the next steps are being sent there. I’m waiting for his eSIM to transfer across but we can’t do anything with the phone now. It keeps asking for verification and saying incorrect information

[Re-Titled by Moderator]

Original Title: What do I do