Can not see the some menu

Hi
in between I can see there is an inventory menu in your tutorial
Please check this article https://wperp.com/docs/accounting-add-ons/inventory/

Here is your screenshot image showing inventory https://cdn.wperp.com/uploads/2019/10/1-inventory-1024×297.png

but on my site, I can not see that. How can I get that?

please check the my menu here https://snipboard.io/rktWQR.jpg

Looking for your help
Regards
Rafilathif