Hello @Thành Đạt Nguyễn ,
Thanks for using Microsoft Q&A forum.
I understand you are having some issues with your Windows 10 product key. I hope you might have look at "Get help with Windows activation errors" , if not then I would recommend you to refer.
In addition to that you can always ask windows community forum for KMS or activation related question or Get help from support.
Hope this helps.
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