Obiettivo «The wolf of Wall Street»

A practical example of how to get this achievement:
https://en.grandgames.net/post/369482

cheers. mastered "the wolf of wall street" in less than 5 days. almost entirely due to the resale of artifacts. Unobtanium at such time, a decent prize))

After morning madness and checking I receive message "Failed!".

First why this, wat is wrong,

Now system give me message. "You do not have the access to this page!" ?

Why this?

This is task: "You need to earn 20,000 coins on the resale of items. Earnings are considered as the sum of all the differences between the price at which you bought any item on the market and the price at which you sold."

What am I doing wrong?