I need to send information asynchronous from content script to popup page sendResponse works fine with synchronous but I don't know how to send asynchronous.
I'm working with Jsforce library works fine
chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
    if(request.action == "rest") {
        if(data.sid==undefined) {
            return null;
        }
        console.log(request);
        conn.apex.get(request.url, function(err, res) {
            if (err) {
                return console.error(err);
            }
            console.log(res); //**works fine but I need return to popup script**
            sendResponse({r: res}); //asynchronous does not work
        });
        return true;
    }
});
 
    