Logs in the user identified by his user ID. This method should be called whenever a user logs in to the host service. This method returns the ID of the newly created session.
|chatId||unique chat ID||string||yes||available in 'INTEGRATION' section of the Chatwee Dashboard|
|clientKey||client secret||string||yes||available in 'INTEGRATION' section of the Chatwee Dashboard|
|userId||user ID||string||yes||obtained with /sso-user/register method|
|userIp||user IP address||string||no||is necessary if ban feature needs to be used against SSO users|