There are two most popular ways to join conferences.
Login using a unique URL. A remote user can give you a unique address, by clicking on which the client of the program will open, and you will be added as a participant.
In the client interface, on the Home tab, select Log In. In the window that opens, specify the unique user ID, additional parameters and click Log In.
Please note that a password may be required to log in, it can be requested from the initiator of the conference.