Hello @Aqil Hidayat - Welcome to Microsoft Q&A community forum!
Thank you for choosing Microsoft Azure. Please find the answers to your questions below:
1) I currently have on-premise servers that is currently on 2012R2, if migrating to Azure, can I specify it to use a 2019 image on Azure? The license will be included in the monthly billing from Azure.
- Azure Migrate does not support server OS upgrade scenario during migration. Currently, it's just lift and shift. It's on the road-map but will not get delivered before year end.
2) If number 1 is not possible, the workaround is to pull the VHD locally and upgrade in place. Do i then need to purchase 2019 license to be able to do that? I would prefer to have the cost included in the monthly billing.
- The license to run Windows Server in the Azure environment is by default included in the per-minute cost of your Windows Virtual Machine.
Licenses for use of Windows Server on-premises (whether in a virtual hard disk (VHD) or otherwise) must be obtained separately through volume licensing.
You can refer to below articles as well for more information:
https://www.microsoft.com/en-us/licensing/product-licensing/azure
https://azure.microsoft.com/en-in/pricing/licensing-faq/
----------------------------------------------------------------------------------------------------------------------
If the response helped, do "Accept Answer" and up-vote it