"Inventory dimension Site is mandatory and must consequently be specified" while transferring WBS to Item requirements

While transferring the WBS estimates to Item requirement of any T&M project in D365FnO, I am getting this error.
"
Inventory dimension Site is mandatory and must consequently be specified

Go to the WBS element and find the item requirements. You need to specify a site on each of those transaction, if there’s not a site on the product by default.

That worked . Thanks Jacob