Source (here) and many many sites inside of China.
A Y-20 aerial refueling variant has been part of the overall Y-20 program from day-one. As such, it is just a matter of time a picture of it surfaces online. No surprise there. Checkbox, check.
Until the new Y-20 Tanker is commissioned with sufficient numbers, the China Airforce has to solider on with a much less capable H-6U fleet and three refurbished Il-78 tankers from the old Ukrainian AF