I can't access Minecraft Dungeons

I have purchased Minecraft Dungeons from the Minecraft Launcher link. However, when I opened the Minecraft Launcher, I could not play Minecraft Dungeons. It said buy now instead as if I had not purchased it. I have checked the support forums and the advice to open it from the Microsoft Store has been unhelpful and irrelevant-I had purchased it from the Mojang Store and should be able to open it from the Minecraft Launcher. If anything, I need direct support from Mojang to access the game or at least get a refund.