Up until 2018 Adobe had no (supported) way to get your custom LUTs into a permanent location. There were some, including hacking your app package, but those were cludgy and totally not supported. One also had to feed the media encoder the same LUTs again... a cluserfsck.
In 2018 Adobe introduced a new way. It's not convenient, but it works and is supported.
Create the following directories, if they do not exist yet:
(where username is your username, obviously)
to make them available for every user
Create these directories:
where username is your username. Alternatively
make them available to every user on the machine.