I don't have an exact source, but I remember him saying how he didn't really want to end up in Russia, how he hasn't adapted super well to it and how he would like to go back to the US if allowed a fair trial.
He already almost martyred himself once to bring us the truth. Why are you demanding he does it again to tell us something everybody already knows?
Does he assume he shouldn't serve time for what he did? Snowden is a complicated figure because the core that the U.S. government was surveilling its own people beyond its bounds was correct.
But he did kind of leak a whole bunch of shit not related to that as well. And that ain't cool.
He kind of has to accept that he's going to go to jail and he's never going to work with sensitive information ever again.
EDIT:
Here's a bit of clarification (quick find on Google, not necessarily the most comprehensive): https://www.france24.com/en/20190916-snowden-says-he-would-r...