Repurchasing the game?

I haven't played Minecraft in a very long time. But I had bought the game back in... 2015 or earlier I guess... When I try load/open the game now it only lets me play the demo Java version of game and not the full game as it use to.

I bought the game so long ago I'm going to be honest I'm not even sure if I had another Microsoft account at the time. But since its auto logged me out, I can not check that. But I can say that I bought it back when the game could only be gotten off the website and you'd only get the desktop item/launcher if you had already purchased the game.

I'm not purchasing this game again. So I hope you can help me fix this.