Error Code:

Error Code	50034
Message	The user account {identifier} does not exist in the {tenant} directory. To sign into this application, the account must be added to the directory.
Remediation	The user that attempted to sign in doesn't exist in this tenant. This can occur because the user mis-typed their username, or isn't in the tenant. An application may have chosen the wrong tenant to sign into, and the currently logged in user was prevented from doing so since they did not exist in your tenant. If this user should be able to log in, add them as a guest. See docs here: https://docs.microsoft.com/azure/active-directory/b2b/add-users-administrator