Take for example, the interface is shown as below.
The Manage Users section will show all users that you create. Moreover, each user can use the
delete button to delete it. For the ACL control, user can specify what topic should be limited. In
this case, we set up the publisher pub1 to write the critical topic. Additionally, we also allow the
subscribers sub1 and sub3 to read the critical topic. Thus, only the sub1 and sub3 can receive
it when pub1 sending the message.