I had purchased minecraft java edition and then afterwards a notificationn showed up saying that i didnt have minecraft on my account and said we had to buy it again
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I think what you are trying to describe here, is that your game is still in demo mode after purchasing it. If this is the case, this report is invalid, as this is an account issue and the bug tracker is unable to help you, as the team do not have access to the appropriate resources. Please read through this article for guidance as to why you are experiencing this problem and for potential steps you can perform, in order to fix the issue. If the problem still persists after following the given advice, please contact Mojang Support. If this is not the case however, please could you provide some more details regarding the issue. Thanks!
Try first closing Minecraft and the launcher completely, and re-open it
Make sure you sign in to Minecraft with the same Microsoft account as the one you bought the game with

Thank you for your report!
We're tracking this issue in MCL-16570, so this ticket is being resolved and linked as a duplicate.
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This is a purchase issue, contact support at https://help.minecraft.net/hc/en-us/requests/new