Move the mouse over your username at the top of the screen.
Click ‘Downloads’ from the drop down menu.
Find related item in your “Downloads” list, click on the Download button, and select “License certificate & purchase code (PDF)” from the drop-down menu.
More Details available at Envato — https://help.market.envato.com/hc/en-us/articles/202822600-Where-Is-My-Purchase-Code-