I want to disable addedit and delete dashboard option for manager inventory role. I tried to handle through permissions as below by giving a fragment type.
There is not option to keep Add widget enabled while disabling Add/Update/Delete Dashboard via permissions, as the same permissions for adding a widget are also used for updating a dashboard.
You can try disabling the Add/Update/Delete Dashboard options via e.g. CSS, but this will not stop anyone from doing these kind of operations via API.