I purchase Minecraft but it's tell me to repurchase it.

I have already purchased Minecraft a few years ago and was playing it about 5 months ago so I recently got a new laptop and wanted to download Minecraft but when I did it only allowed me to play the demo and told me to purchase it again. But in my other computer didn't do that if you also like to know I purchased java edition in Minecraft.com not the Microsoft store and I purchased it with a gift card.