I have a search bar in my chrome extension popup (V3), that directly opens the search-url on a specific website.

function fixedEncodeURI (str) {
    return encodeURI(str).replace(/%5B/g, '[').replace(/%5D/g, ']');
}

$('#searchBtn').click(function(){
    if(search) {
        var bookUrl =  "https:// <!-- Website --!> /search/?q=" + fixedEncodeURI(search);
        var createData = {
            "url": bookUrl,
            "type": "popup",
            "top": 5,
            "left": 5,
            "width": screen.availWidth/2,
            "height": screen.availHeight/2
        };
        chrome.windows.create(createData, function(){});
    }

});

Now I would like to change this, so the extension retrieves a price tag (specific div with given id) from the same url and shows it in my extension, without the window opening visibly.

I neither have API access to the website nor is it my own database behind it.

Is there a way of doing so? And what methods should I look into?