Get your apikey:

1. Open https://stooq.com/q/d/?s=&get_apikey
2. Enter the captcha code.
3. Copy the CSV download link at the bottom of the page - it will contain the <apikey> variable.
4. Append the <apikey> variable with its value to your requests, e.g.
   https://stooq.com/q/d/l/?apikey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX&i=d&apikey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX