All Live Assist actions including monitoring and engaging with consumers are triggered only when a web page conducts a ‘page load’. Single page applications do not have page loads and therefore are unable to take advantage of many critical Live Assist functionality, out-of-the-box.
However, you can call a javascript method from the Live Assist tag, which invokes the engagement as if a page had been navigated. You'll need to have setup an engagement that matches the url or sections you pass in. Here's a an example snippet:
lpTag.newPage("https://example.com/spa-support", { section: [ 'section' , 'section2'], sdes: [ { "type": "cart", "total": 11.7, "numItems": 6, "products": [ { "product": { "name": "prod1", "category": "category", "sku": "sku", "price": 7.8 }, "quantity": 1} ] } ], taglets: { rendererStub:{ divIdsToKeep: { "divId": true } } } });