RN
There is a date attached to this question, and it is 23 February 2022.
That is the day Roku switched off non-certified channels — the things everyone called private channels. Not deprecated, not hidden further: disabled. They could no longer be installed, they could no longer be launched, and the ones already sitting on people's devices were removed automatically.
The 2021 version of this article explained how to use exactly that mechanism. Sign in on the website, go to the account page, enter a code, add the channel. Those steps were correct when they were written and stopped working just under a year later, which is the single most useful thing anyone can tell you about this topic.
Why the workaround was the whole answer
Roku's public Channel Store is curated. Submissions go through certification, and that process screens for sexually explicit material and rejects it, so adult apps are not publicly listed and never were.
Private channels were the gap in that fence. A developer could publish outside the store and hand out a code; a user could enter the code and install something the store would not carry. Every set of instructions for watching adult material on this hardware, including the one this page replaces, was really just instructions for using that gap.
Close the gap and there is no second route. When the mechanism went, the answer went with it.
The replacement is not a replacement
Roku did put something in its place. Beta channels exist for developers who need to distribute outside the store.
They come with two hard limits. A beta channel takes a maximum of twenty users, and it expires 120 days after creation unless the developer renews it.
Twenty is the number that matters. It is a testing allowance, not a distribution channel, and it makes the old model arithmetically impossible — no service can operate an audience through a door that admits twenty people and closes every four months. Any page you find in 2026 offering beta codes as the modern version of the private-channel trick is describing something that cannot work at the scale it implies.
What is actually left
One thing, and Roku documents it itself: screen mirroring from a phone, tablet or computer to the streaming device.
Understand what that is, because it is not a channel and does not behave like one. The Roku is not fetching anything. Your phone or laptop plays the video and relays its display to the television, which is why platform curation does not enter into it — nothing is being installed and no store is involved.
The consequences follow from the same fact. Whatever is on the source screen goes to the television, including notifications arriving mid-playback. Quality depends on the local network rather than on the streaming device. The source device is doing the decoding, so it warms up and the battery drains. And you are driving everything from the phone rather than from the remote, which is a different experience from the one people are usually imagining when they ask this question.
For a lot of people that is fine. It is worth knowing in advance that it is a mirror rather than an app, because expecting an app and getting a mirror is where the frustration comes from.
The general lesson, which is worth more than the specific one
Instructions that depend on a platform gap have a shelf life set by the platform, and the platform does not announce it to the people relying on it.
The tell is in the phrasing. When a how-to tells you to enter a code, sideload something, use a non-standard sign-in path, or reach a settings page that the normal interface does not link to, it is documenting a gap rather than a feature. Features get maintained. Gaps get closed, usually without warning, and the article describing them stays online looking perfectly authoritative long afterwards.
Check the date on any device guide before you follow it, and check whether the step it hinges on is something the manufacturer supports or something it merely has not stopped yet. On this hardware, that distinction was settled on a Wednesday in February 2022. If you want a device-based route to this material, the honest advice is to pick a device that has a general-purpose web browser, and let the browser do the work.