'Hacking' Facebook Messenger games using Firefox
1 | Fire up Firefox 2 | Sign into Facebook or the lesser-known http://messenger.com3 | Open a game4 | Open Developer Tools (F12)5 | Goto the network tab (Click clear & click the "JS" filter)6 | Start playing the game until you fail7 | Close the game8 | In the search box in the top right of the Network tab, type in "/m" and it should appear with the save-game requests.9 | Click the LAST "/webgraphql/mutation/?doc" request10 | Click "Edit & Resend"11 | Either in the URL box or the box that is marked "Query String", find the "score" variable. Shout look like this: "score":400,"12 | You don't neeed a score of 400, but when you find the score you can freely modify this value.
video link
credit to (FatMonsterIsEatin)
https://www.youtube.com/channel/UC83pJqKlQxSPGkI3T0dLZAg