Use Chrome on a PC/laptop (phones and tablets aren't supported for getting the token. After getting the token, you can share the token to your phone and use this tool in your phone).
Open Duolingo site.
After the page has loaded, right-click anywhere and press Inspect (the lowest option).
After a menu opens on the right, press the Console tab.
In the console textbox, type allow pasting and press Enter (if an 'Uncaught SyntaxError' appears, that's okay).
Then, copy this code and paste it into the console textbox and press Enter: function getCookie(name) { const value = `; ${document.cookie}`; const parts = value.split(`; ${name}=`); if (parts.length === 2) return parts.pop().split(';').shift(); } getCookie('jwt_token');
The token will appear. Right-click on the token and press "Copy string contents".
Paste the token into the API Key input box on this site. Your API Key will be saved in your current browser so you don't need to fill it everytime.