About 5 minutes, one time.
Open your web browser (Chrome) and go to:
chris-tv.duckdns.org/apkIt downloads the app. Open the downloaded file — tap the download bar, or find chris-tv.apk in Files / Downloads. When your phone asks, allow your browser to install unknown apps (a one-time toggle), then tap Install and Open.
No “developer mode” needed on a phone — you just allow the install when prompted, then turn it back off if you like.
Then jump to step 4 below (enter your access code).
On your Fire TV remote, press the magnifying-glass / Search, type Downloader, and install the orange Downloader app (by AFTVnews). It's free.
Go to Settings → My Fire TV → Developer options → Install unknown apps, find Downloader and switch it ON.
Don't see “Developer options”? In My Fire TV → About, highlight your device name and click it 7 times — it appears after that.
Open Downloader. In the box, just type this code:
8222161Press Go. When it finishes downloading, click Install, then Open.
(Prefer a link? You can instead type chris-tv.duckdns.org/apk.)
When Chris TV opens, type the access code you were given (looks like XXXX-XXXX) and press Activate.
Tap Add account, choose Xtream, and enter your Server URL, Username, and Password (from your IPTV provider). Tap Connect — your channels load in a few seconds.
You only do this once per device. Your login stays on your device.