How to reinstall Minecraft Java?
Years ago, I purchased Minecraft Java Edition. Eventually I broke that laptop, and on my new computer the website wants me to buy the game again. I did have to re-download the game once on my old laptop, so I know I should be able to re-download it now. I also know for sure that it is the same account. How can I re-install Minecraft?
The answer to your question - how to reinstall Minecraft Java is -
Log back into the account on the new computer, then download the Launcher.
Afterwards, run the Launcher and download the versions you want.