this is the entirety of what this extension does, from its code:
// Extract the search query from the DuckDuckGo URL
const url = new URL(tab.url);
const searchQuery = url.searchParams.get('q');
if (searchQuery) {
// Create the Google search URL
const googleUrl = `https://www.google.com/search?q=${encodeURIComponent(searchQuery)}`;
which is identical to what appending !g to a DDG query does