i try to make destructable meshes but the nvidia plex plugin is not in the engine
how can i install it
would you happen to mean APEX or FLEX?
under the plugins selector, you can select the built in drop down, then in the search at the top right corner search for that plugin.
Now if you are looking for the specific like the NVIDiA UNREAL FORK
here
YOU WILL NEED TO BE SINGED IN TO GIT HUB, and might also have to be linked to the epic games source