send screenshot to notion

Question

I'm learning JavaScript and I decided to make a Chrome extension that will take a screenshot and send it to a notion page. I make the screenshot from thee background.js and send it to the content.js:

chrome.runtime.onMessage.addListener(
    function(request, sender, sendResponse) {
    if (request.message === 'capture')
   chrome.tabs.captureVisibleTab(
       null,
       {},
       function(dataUrl)
       {
           sendResponse({imgSrc:dataUrl});

       }
   );
   return true;
});

The problem is that to send the image to notion using the notion API I need the URL of the image; how can I get that url? Is there any way I can convert that screenshot to a URL and be able to send it?

I tried to send the dataURL received by the background.js but it gives me back an error:

  const options = {
      method: 'PATCH',
      headers: {
          accept: 'application/json',
          'Notion-Version': '2022-06-28',
          'content-type': 'application/json',
          'Authorization': 'Bearer ' + token.access_token
      },
      body: JSON.stringify({
        "children": [{
          'type': 'image',
          'image': {
              "caption": [],
              'type': 'external',
              'external': {
                  'url': image_url
              }
          }
      }]})
    };
    fetch(`https://api.notion.com/v1/blocks/${page.id}/children`,
    options
   )
      .then(response => response.json())
      .then(response => console.log(response))
      .catch(err => console.error(err));   
  
}