On Microsoft's App Registrations page, when you create an app for the Zoho Vault service, you have to configure the option Accounts in any organizational directory (Any Microsoft Entra ID - Multitenant) and personal Microsoft accounts (e.g. Skype, Xbox).
If you configure the "Supported Account Types" as Personal Microsoft accounts only or Accounts in any organizational directory (Any Microsoft Entra ID - Multitenant), you may get this error message while generating the token.