Sofas can't be synthesized and can only be purchased through shopping malls.

The steps to buy a sofa are as follows:

1. Open the Fat Goose Gym and slide down into the free zone;

2. Enter the interface and click the store;

3. Enter the interface and click on the sofa;

4. Enter the interface and click Buy.

Gold coins can be accumulated through tasks. You can buy a certain amount of gold coins in the mall buy buy.