Submitting a form to multiple URLs

I am currently trying to learn html and wanted to create something as I was learning. I am trying to create a search box which would retrieve results from multiple sites. So far only the first site that is in action works but not the second one. I tried searching a lot on google but was unable to find anything, I also tried checking here but did not seem to find anything. I am only trying to have the search box get results from multiple different sites.

<!DOCTYPE html>
<html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>Test</title>
    </head>

<body>
    <h1>Search for a Domain or IP</h1>
        <form method="get" action="https://www.virustotal.com/en/domain/%s/information/","https://duckduckgo.com/search.html?prefill=Search DuckDuckGo" target="_blank" onsubmit="submitSearch()">
        <input type="text" placeholder="Search..." required>
        <input type="button" value="Search">
    </form>
</body>
</html>