should be 3rd to 4th quarter of this year if they are following time table set at last call
That's when the 5th generation prototype should be finished, which is "semi-commercial prototype", capable of faster run times and higher volume output than 4th gen.
But to, as I said, "prove (assuming they do prove) commercial viability, finding customers / partner / buyer, etc.", that's all 2022, and probably late 2022.