Hi @IBN
I did a test in our environment and you could try to follow these steps to see if works for you:
1) As the global admin, you could try to login to Office 365 admin center
2)In Office 365 admin center, click Users > Active Users > select the users you need to assign(very important, or you cannot see the assign license option) > click "..." > click Manage product license
3)Based on your requirements, you could choose these options to assign license to multiple users.
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