I can customize the office 365 account here, he can only customize the account name, not the domain name.
The name can be specified by you, but the domain name is uncertain. It may be @365up.site, @taylkjt.onmicrosoft.com, or @s3km.a1p.me, @taylkjt.onmicrosoft.com, etc.
eg:
name: 025678
account:
025678@365up.sitepassword: 123456
my Skype:
lt2952371168@outlook.comYou are welcome to find me to customize 365 account.