At the moment, the timing is unknown, but even in the case of the worst circumstances, it will be released on Steam.
If we take into account the best development option, then it may take a year for the game to get on Steam with the Early Access tag. If we talk specifically about the release version of the game, then it will take a little more time, but no more than two years. But this is in the event that donations will either increase or stagnate. If they decline, then the deadlines will be many times higher, because the number of people working on the game will have to be cut.