Dear Sawid,
First of all, thank you for the purchase!
You can assign your menu to the desired location in the top-left box of the “Appearance – Menus” section in the theme admin area. In the dropdown which says “Main Menu Above Content”, choose the menu you wish to display below the header image/slider and click “Save”.
Please note that I try to answer every support request as quickly as I can, but I am not online 24/7, especially on weekends, thus it is worth posting a question at least one or two days in advance in case an issue is urgent.
Should you have other questions, do not hesitate to approach me!
Sincerely,
Andrew | Satori