Full line code completion for c++ do not work

Can anyone give me help . I can not find the place which the doc said to enable the c++ full line completion function :(

Yiman0919, CLion Nova is required to use Full Line Code Completion with C/C++. Is it enabled in your CLion (https://www.jetbrains.com/help/clion/clion-nova-introduction.html#switch-to-nova-via-settings)?

Anna Falevskaya, this option is not enabled.  After open this option, the Full Line Code Completion with c/c++ can work. Thanks!