The autosave from kong is stored in your browser, in IndexedDB. Here are the general steps to extract it and save to a file.
<iframe src="https://game287709.konggames.com/"></iframe>
const req = indexedDB.open('/idbfs');
req.onsuccess = () => {
const db = req.result;
const store = db.transaction('FILE_DATA', 'readonly').objectStore('FILE_DATA');
const cursorReq = store.openCursor();
cursorReq.onsuccess = e => {
const cursor = e.target.result;
if (!cursor) return;
if (cursor.key.endsWith('/NGUSave.txt')) {
const contents = cursor.value.contents;
const bytes = new Uint8Array(Object.values(contents));
const blob = new Blob([bytes]);
const a = document.createElement('a');
a.href = URL.createObjectURL(blob);
a.download = 'NGUSave.txt';
a.click();
} else {
cursor.continue();
}
};
};