You go to help, pick a subject and scroll down. It should say is this help helpful or did this answer your question. Something along those lines. If you click it then click no, when a yes no option is presented to you, it will give you an option to speak to live chat.
However, not all subjects you are looking answers to will have this option at the bottom (For some strange reason) …You just have to click on another help section, scroll to the bottom of it and then press no when asked if the help provided solved your query. You will then get the option to speak to live chat.