No, Smart IPTV application does not include any channels and no information will be provided about where you can get channels or channel packages. Also, application developers are not responsible for the content uploaded to Smart IPTV.
It means you have installed the application through Google Play Store and can only pay for the app inside the app in Settings -> Device Info -> Activate. MAC address is no longer accessible for apps in the Google Play Store, a temporary Device ID is used. Install the app manually to use other payment methods or if you get In-app billing service is unavailable error (Android 12 and older only).
MAC address is no longer accessible for apps in the Google Play Store, a temporary Device ID is used. Install the App manually to retrieve your MAC address and avoid extra payment for the App.
Each TV has 2 MAC addresses (1st is WiFi, 2nd is Ethernet) and a 2nd MAC is activated automatically after you switch to another connection type and restart the app. MAC address is unique for every TV and cannot be changed manually.
Since app version 3.0.0 for LG webOS TVs, there is no access to MAC address, so only device ID is available in the app, but it will be activated automatically after app launch if you activated your TV before. You can use your old MAC to upload playlist too.
Try changing DNS entry of your TV/device/PC/router network settings to 1.1.1.1 or 8.8.8.8 and see if it helps.
You can also try using VPN services on mobile devices to access the website.
Try example test list http://siptv.app/lists/example.m3u (external URL) first, then then check your playlist for errors. Make sure your URL is a direct link, not a redirect and that it is currently online. You can also try downloading your playlist file by putting the playlist URL in the internet browser address field and use it as a static playlist at My list page.
In case of Check playlist URL you can try turning off your TV/device from power cord for ~1 minute to clear device cache. Also try long pressing "0" or "CH", or long mouse click "Reload" button to force reload of playlist URL (disable app cache).
Additionally, try reducing your playlist size by removing channels/movies (especially if you have LM series LG TV with limited memory), disable external EPG or uncheck Detect EPG box, when uploading your playlist. If your playlist doesn't appear on TV or disappears after restart, try checking Save online box. You can also try resetting Smart HUB or turn your TV off and on to clear the TV cache if you have Samsung TV.
TVs have limited memory available for app storage, so if your playlist is too big, it might fail to save in TV's memory.
Try example test list http://siptv.app/lists/example.m3u first, then make sure all your stream links work (not dead) and codecs are supported by your TV. Every TV make and model are totally different and may or may not support specific stream formats: