At fist,you need already have an A1 or A1 PLUS or E5 account.
- Click this link: https://aad.portal.azure.com/#blade/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/Overview
- Follow the picture instructions
If this prompt appears, please ignore it.
Click Users on the left.
Click on the user name you just created.
Fill in a password or choose to automatically create a password,and Tick Show password to save it.
Set roles to administrator