Regarding life link
Source:
https://unity.com/releases/2019-3/dots-sample#unity-live-link
There is info what is primarily required.
Link in this post may be useful, if someone is interest in life link.
In the article, need scroll down, toward the end.
https://gametorrahod.com/game-object-conversion-and-subscene/
At current state, it is not as easy to setup, but it is functional.
However, I wouldn’t recommend it for a production.