I'm a beginner in js and trying to code a plugin using "downloads"-API. Sadly I can't find out what's wrong. The console gives the following Error: " main.js:6 Uncaught TypeError: Cannot read properties of undefined (reading 'onCreated') "

Manifest:

{ 
    "manifest_version":3,
    "version":"1.0",
    "name":"Test",
    "content_scripts":[
        {
             "matches":["<all_urls>"],
             "js":["main.js"],
             "permissions":["downloads"]
        }
    ]
}

main.js :

function handleCreated(item) {
    console.log(item); 
}
chrome.downloads.onCreated.addListener(handleCreated);

The error occurs directly after the DOM is loaded, so it does not even recognize that it should wait until a download has started. Any idea?

thx a lot!