Apply a transformation to new data table, csv etc

[ilcaa]

i have a transformation on a table... i want to apply the same transformation on a new CSV file or Table basically a new "Source"

how do i "point" an existing transformation to a new different csv, or table or other input (obviously with same structure)

i created a function out of my original transformation, i imported a new data as a Table... when I try to invoke a function by Add New Column it ask me for a column name
what is the proper way to apply to new imported Source ? thanks

(bin as binary) as table =>
let
    Source = Folder.Files(bin),
    
    promote= Table.PromoteHeaders(Source, [PromoteAllScalars=true]),
      
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Product", type text}, {"ZN(COUNTD([accn_id]))", Int64.Type}}),
    #"Renamed Columns" = Table.RenameColumns(#"Changed Type",{{"ZN(COUNTD([accn_id]))", "tests"}}),
    #"Removed Columns" = Table.RemoveColumns(#"Renamed Columns",{"Source.Name"}),