M365 - uprgrade Windows 10 LTSB/LTSC and Windows 8.1

[NowITmark]

My customer has Windows 10 LTSB, Windows 10 LTSC and Windows 8.1 Enterprise and want buy M365 E3. Is it possible to upgrade mentioned version of Windows to Windows 10 Enterprise E3? If yes, how can I do it?

[#2]

@NowITmark did you ever figure this out? we have the same question