IPTV is commonly broadcasted in mpegts.... Chromecast is not compatible for this. Most stream directly from Android TV box or fire 🔥 stick for this.
Best thing to do is download VLC player, load your playlist and then cast from there.
I just use Smarters and GSE IPTV for Apple. Once you buy it, you shouldn’t have to buy it again if it’s all under the same account.
This issue is that your stream is MPEGTS (or TS).
You might be able to get around this by swapping the output_type=ts on your URL to output_type=hls.