This is most likely a temporary issue, but please try logging out/into your Mojang/Microsoft account in-game, and restart your launcher. If the problem persists, please contact us here help.minecraft.net/hc/en-us/… with your receipt and we'll assist as soon as possible. ^SA

After following your advice for filing a request, a week has passed and I’m still unable to play on my realm I paid a subscription for. This is unacceptable.