Important: you need to have your documents with you. The trail is located in a border forest (not even a zone). Ideally, you need to get a permit, especially for foreigners. Or at least call the border committee. Otherwise, it is not a fact that you will be able to get to the place. If you try to go without warning, you will most likely be let through, but of course there are no guarantees.
Entrance to the trail is conditionally paid. 3 rubles. You can use the QR "Pay". No one checks, on your conscience.