Need help with the Show Groups request in Documentation

[Jalani E.]

Greetings everyone: 

I am having trouble getting a valid response back from the server when I try to get a specific group by ID. For example, using the following command: 

curl https://api.groupme.com/v3/groups/:id?token=mytoken123&id=123456789

Returns the JSON:

{"meta":{"code":400,"errors":["param is not a number"]}}

I thought I was passing the parameter in the query string properly but I do not know. Any solutions to this? I would really like to get a group by ID instead of parsing through an entire set of groups with hundreds of members.