How do I upgrade to Windows 10 in an organization?

Question

Windows

In an OEM organization, Windows 7 licenses were purchased with computers.
The computers have the appropriate stickers and the invoice says windows 7.
How can I upgrade to windows 10 from a legal point of view and insure myself against licensing problems?
Has anyone already had experience of communicating with inspection organizations after the upgrade?
Has someone already requested some kind of paper confirming the legality of such an upgrade?
What is written here is not official, but written by the wiki author and replicated everywhere by him:

Legality of a free transition to Windows 10 for inspection bodies
According to Art. 435-449 of the Civil Code of the Russian Federation, the Windows offer for a free upgrade ( www.microsoft.com/ru-ru/windows/windows-10-upgrade...
is a public offer. Since it fully complies with the requirements of Article 437 of the Civil Code of the Russian Federation.
In accordance with the above articles and Art. 1286 acceptance of this offer will be the beginning of the use of the software, which means the user's consent to conclude an agreement and acceptance of the Windows 10 End User License Agreement (EULA) and the terms of the offer. Therefore, no additional documents, except for documents confirming the legality of the use of the corresponding operating system by the user, from which the free upgrade to Windows 10 is allowed, are required to confirm the legality of the upgrade.
Of course, you have every right to ask Microsoft, and its affiliate, which has the right to distribute corporate software in our region, about the absence of claims against your organization and the Rights Granted to you, under license agreements. But this can already be only your own initiative.

But how do you document the existence of a free upgrade offer?

Answer 1

You yourself wrote the answer of the
Offer is enough.
If you want to make sure - ask M$ for official confirmation of the offer.

Answer 2

a request is made from the melko-soft ones for confirmation.