If you bought the game directly from Frontier then log in to https://www.frontierstore.net then go to "My Downloadable Products" and download the launcher there.
So, if you moved from console to PC, there's nothing in your downloadable content? What if, gods forbid, I lose my current install or have to reinstall? There's literally nothing for me to download. And, if not obvious, I'm also new to PC ....
2. If you were given a free PC account then I would assume you should have a download available in your "Downloadable Products" page as @Robert Maynard says.