Unable to activate MacBook Air after erasing data

I'm experiencing this problem with my MacBook Air after data erasing. Do you know how to fix it? I've already spoken to the customer, so please help me.

Apple MacBook Air Core i5

8th Gen - 8 GB/256 GB SSD

/Mac OS Mojave MVFN2HN

/A

[Re-Titled by Moderator]

Original Title: MacBook Air problem