The message

Try Hi! I have a question about {title}. On a product page the title is the product’s name. Add {url} when you want the address as well: Question about {title}: {url}.

Where to show it, and where not

Product pages and the pages around them are the ones that matter. A cart and a checkout are where you want the buyer to finish, so leave the button off those by listing their page numbers. Category pages and search results have no number of their own, so with that setting they keep the button.

It is not tied to a shop plugin

Beckonbird does not look at your cart, your products or your orders. It works the same on any theme and with any shop plugin, because the only thing it reads is the title and the address of the page. That is also why it does not know which products are in stock, and why you should keep prices, and any card details, out of the chat.

When you are away

A shop is open all night and you are not. Put when you answer in the greeting. If you want the button to say so itself outside your hours, that is a Pro setting; it is described in the guide to opening hours.