01) Access the Control Panel
02) After login click on Configuration >> Product Listing >> select the options below and click on EDIT
Percentage to increase fake price special all products
Set a percentage to increase on all products as if it were in promotion, only numbers. Example: 15 (15 equals 15%)
Enable / Disable fake price special all products: true = enable / false = disable
Enable or disable this feature
After clicking on the UPDATE button
Note: This feature will enter the price increase on all products as if it were on sale.