Blank Column with when using calculate

Hi there Just starting my power BI journey so I apologise if this has come up before I am working through some tasks and learning DAX functions the task is to use the calculate function
Again, from Home, click on New column, and type the following (the expression will be evaluated based on the filter ‘Europe’):
European Sales = CALCULATE (FactInternetSales [TotalSales], DimSalesTerritor[SalesTerritoryGroup] = "Europe")

The Total sale is a measure that was calculated in the previous step. When I input this the next step the columns is created but everything is blank and I am unsure what I have done wrong