The 'set queue auto' command enables or disables automatic queue entry. If auto is enabled, users who join the channel will be put in the queue automatically and will not be permitted to leave the queue unless they leave the channel (or a channel operator removes them from the queue).
/as chan <room> set queue auto enable
Normally you will want your users automatically placed on the queue when they arrive in the channel. Otherwise they would have to manually ask to be added very much like take-a-ticket in stores.