Minecraft on Switch: We are still working on a fix. However, for a temporary workaround, try not signing in to a Microsoft account. While you won’t have access to servers, Realms, or possibly Marketplace content, you will be able to play single player & split-screen worlds. - HZ

I have waited 2 weeks in the mojang support email without replay, I told you that I don't have accest to the account nor to the email but I know the security questions cmon