Three ways to put chat on a Joomla site
A live-chat extension from the Joomla Extensions Directory. Straightforward, and entirely dependent on someone being available to answer.
A universal widget pasted into your template before the closing body tag. Any vendor, any site; it reads your published pages, not your store data.
A native Joomla extension connected to your account, which syncs your content and, on VirtueMart or HikaShop, your catalogue and orders. This is the only option that can answer "where is my order" without a person.
Vatdi is the third kind, for Joomla 5.x and 6.x.