On facebook in a iptv group someone had posted a test line. I managed to save her and the quality of the TV channels was excellent. The 4k TV detects them as UHD resolution.
How can I find out who's the iptv service provider?
The line was http://185.132.134.138:6969/get.php?username=adanateknoshopgsm1&password=B7t5YOG6&type=m3u_plus&output=m3u8
Why not ask the person that posted the test stream? A quick Google search shows that Tekno Shop GSM is some international mobile phone store. I guess they're no less reliable than a random stranger you meet on Reddit offering a service.