You can run ARDL model when variables are I(0) and I(1) but should not be I(2). I have made ARDL model video and put it in EVIEWS section of Hossain Academy below. You can check it.
It would be better to employ ARDL when dependent variable is in I1 integrated but in some models can be used and some independent variables in 10 and some in I1 become stationary. And no variable in 12.