You need to track data changes in MongoDB, but how?

Question

MongoDB

I have a bot in discord, and let's imagine such a situation that let's say someone gave someone a balance, and the user's balance in the database has changed.
In the database, for example, the user had 120 balance, and after the change it became 180, how can I track which field has changed, and what was the value in this field before?

I searched the MongoDB documentation and only found this . After reading everything, and following the example by writing a small code - I decided to test it. After changing the document in the database, the already changed document was displayed to me in the console, with a new value in the field. Tried to google, but unfortunately without success.