Hi @Dao Ngoc Thanh - Thank you for contacting us!
If you have an EC2 instance then it’s highly likely you’re using an AWS market place image. If so, you’ll be renting the license and therefore no SQL licence would be applied after migration to Azure.
Alternatively, if you used your own license then you should be able to re-use this license on Azure as long as you have Software assurance.
Which scenario are you looking at?
----------------------------------------------------------------------------------------------------------------------
If the response helped, do "Accept Answer" and up-vote it