Are you trying to GET for 2 users?
You can’t seperate the users by a coma. they each need to have ‘login=’ or ‘id=’
A request can include a mixture of login names and user ID. If specifying multiple values (any combination of id and/or login values), separate them with ampersands; e.g.,
GET https://api.twitch.tv/helix/users?login=<login name>&id=<user ID>...
GET https://api.twitch.tv/helix/users?id=<user ID>&id=<user ID>...GET https://api.twitch.tv/helix/users?login=<login name>&login=<login name>...
Source: https://dev.twitch.tv/docs/api/reference/#get-users
so instead of
-X GET https://api.twitch.tv/kraken/users?login=dallas,dallasnchains
try this
-X GET https://api.twitch.tv/kraken/users?login=dallas&login=dallasnchains
UPDATE: I was thinking you were using Helix, not Kraken. Going to leave this for a reference in case anyone needs it in the future.