It seems it should work but it didn't for me (and error is not clear enough)
$ labels ... a-private/repo
>> No permission, enter your username and password:
[?] username: MoOx
[?] password: **********
[?] code: {github code received by sms}
Existing token found!
>> Authorize error
OAuth2 authentication requires a token or key & secret to be set
Any idea what am I doing wrong?