UPDATE TCL OLD ANDROID

Please help me to update my TCL. My tv android smart tv but it just have some useless apps in its app store. Only useful app is Youtube and Mirrorcast , I don't have Netflix prime or an other applications. Also when i try to update , it says Its already the latest version so please help me to flash a good system and download link.

My current model TCL L50P1US
Software: V8-S68AT02-LF1V074