You haven’t been looking very hard —
There’s no witness listed in the article you linked. It’s nothing more than a propaganda piece rehashing the alleged twitter and youtube, which as I stated is not evidence as both are easily faked/hacked. The globalist MSM in the US and Europe print the accusations against Russia and don’t present any analysis of the truth or error of the accusations.
All propaganda, to inflame the public of Europe and the USA against Russia, to divide Russia from European commerce. Logical questions go un-asked.