dataware house measures without a corresponding dimension

I have an operating system that contains this table

salesQuality salesPrice salesCategory

according to my business requirements, the salesQality and salesPrice are measures,

however, salesCategory is a dimension.

but, unfortunately, in the operation database, i do have some raws without the salesCategoryvalue.

my question is what should I do in the fact table to represent these sales that don't have a category value in the category dimension?

Thanks