In the article it mentions yuan denominated letters of credit. I also do know that China and Russia were working on a separate transaction system, but I don't know about its progress. There is one thing for sure: this situation might force Chinese businesses and banks to start using more of their own nation’s currency.
There were reports that less than 50% of Russia-China trade was transacted in USD.
It was a rapid drop. That means for Russia-China trade, the USD is on its way out of the picture.
Depending on what happens next in Europe, they might not use any USD in Russia-China trade.