Mixed Content: The page at '<URL>' was loaded over HTTPS, but requested an insecure element '<URL>'. This request was automatically upgraded to HTTPS, For more information see <URL> code example

Example: How to fix 'Mixed Content: The page was loaded over HTTPS, but requested an insecure script” [duplicate]

If you get a console message that a resource request has been automatically upgraded from HTTP to HTTPS, you can safely change the http:// URL for the resource in your code to https://. You can also check to see if a resource is available securely by changing http:// to https:// in the browser URL bar and attempting to open the URL in a browser tab.
https://web.dev/fixing-mixed-content/