As for saying a cue/ command. The way dogs process information and learn cues is linear. Dogs can learn by labeling, meaning you say the cue as you do it, however it is more effective to say the word before as a prompt.
The click is to mark the exact moment the dog does something you want, offers the desired behavior. You ask for a behavior such as “sit”, the dog does it (as the dog is doing it- you click). The click becomes an affirmative marker that that behavior was correct and the dog will now also anticipate reward. The clicking is a marker. You can say “good sit” afterwords but that is a label. Labels can be reinforcing of a principle.
You use the same technique with clicking with whatever it is you are trying to achieve.
Example: You are trying to teach a lie down and Fanny already knows sit. You ask her to sit. She does. You then prompt “lie down” and lure her into position (this is just one example). The moment she lies down, or gets close if that’s as good as you can get right now, that’s when you click. It can work in incremental stages, that’s whats great about using clickers to help you reach end criteria. Let’s say at first she only would put her elbows down but wouldn’t actually be lying down. You can start by rewarding for more and more of the desired behavior.
Watch the video again by Ruth LaRoque and notice when she is saying her command/ cue words vs the click.
If you have video of it, we can better point out moments and what you are doing which may be able to better help illustrate this idea.