Adds a User to a specific List by its ID.
The access token received from the authorization server in the OAuth 2.0 flow.
The ID of the List for which to add a member. The unique identifier of this List.
"1146654567674912769"
Unique identifier of this User. This is returned as a string in order to avoid complications with languages and tools that cannot handle large integers.
"2244994945"
The request has succeeded.
1An HTTP Problem Details object, as defined in IETF RFC 7807 (https://tools.ietf.org/html/rfc7807).