let
    //Define function taking two parameters - a table and an optional column number 
    Source = (TableToExpand as table, optional ColumnNumber as number) =>
    let
     //If the column number is missing, make it 0
     ActualColumnNumber = if (ColumnNumber=null) then 0 else ColumnNumber,
     //Find the column name relating to the column number
     ColumnName = Table.ColumnNames(TableToExpand){ActualColumnNumber},
     //Get a list containing all of the values in the column
     ColumnContents = Table.Column(TableToExpand, ColumnName),
     //Iterate over each value in the column and then
     //If the value is of type table get a list of all of the columns in the table
     //Then get a distinct list of all of these column names
     ColumnsToExpand = List.Distinct(List.Combine(List.Transform(ColumnContents, 
                        each if _ is table then Table.ColumnNames(_) else {}))),
     //Append the original column name to the front of each of these column names
     NewColumnNames = List.Transform(ColumnsToExpand, each ColumnName & "." & _),
     //Is there anything to expand in this column?
     CanExpandCurrentColumn = List.Count(ColumnsToExpand)>0,
     //If this column can be expanded, then expand it
     ExpandedTable = if CanExpandCurrentColumn 
                         then 
                         Table.ExpandTableColumn(TableToExpand, ColumnName, 
                                ColumnsToExpand, NewColumnNames) 
                         else 
                         TableToExpand,
     //If the column has been expanded then keep the column number the same, otherwise add one to it
     NextColumnNumber = if CanExpandCurrentColumn then ActualColumnNumber else ActualColumnNumber+1,
     //If the column number is now greater than the number of columns in the table
     //Then return the table as it is
     //Else call the ExpandAll function recursively with the expanded table
     OutputTable = if NextColumnNumber>(Table.ColumnCount(ExpandedTable)-1) 
                        then 
                        ExpandedTable 
                        else 
                        ExpandAll(ExpandedTable, NextColumnNumber)
    in
     OutputTable
in
    Source

let
    Источник = Json.Document(Web.Contents("https://api-fns.ru/api/check?req=[INN]&key=[API_key]")),
    #"Преобразовано в таблицу" = Record.ToTable(Источник),
    Output=ExpandAll(#"Преобразовано в таблицу")
in
    Output

= Json.Document(Web.Contents("https://api-fns.ru/api/check?req=[INN]&key=[API_key]"))