Hi Tung,
Welcome to Q&A Forum; this is a great place to get support, answers, and tips.
Thank you for posting your question; I'll be more than glad to help you out.
As you are already on Azure, of course, you can buy a license wherever you want (there are a lot of license shops out there), but I would recommend deploying a new Azure VM with SQL Server configuration and a SQL Server installed. In this way, you can benefit from the optimal configuration of a SQL Server and the attached license. You only pay for those licenses when your VM is up and running... and if you remove your VM you automatically stoped paying for those licenses.
This might be an option for you.
I hope my answer is helpful to you,
Your
Bjoern Peters
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