Yes. But it's a herculean task.It is certainly possible. There are enough players who have demonstrably won so much money online. I think the question should not be whether you can win so much but "when" you can win so much.
Then, of course, it must be clarified whether you can win the million in one tournament or in several. The second is much more realistic. In only one tournament is actually a lot of perseverance and some luck needed but also not impossible.