Properly load JSON file

Sab ,

This one with headers.

let
Source = Json.Document(File.Contents("D:\Downloads\example.json")),
#"Added Custom" = Json.Document(Source),
#"Converted to Table" = Record.ToTable(#"Added Custom"),
#"Added Custom1" = Table.AddColumn(#"Converted to Table", "Custom", each if [Name] = "column_definitions" then
Table.Transpose(Table.FromList(List.Transform([Value], each Record.FieldNames(_){0}), Splitter.SplitByNothing(), null, null, ExtraValues.Error))
else
Table.Combine(List.Transform([Value]
, each Table.Transpose(Table.FromList(_, Splitter.SplitByNothing(), null, null, ExtraValues.Error))))),
#"Removed Other Columns" = Table.SelectColumns(#"Added Custom1",{"Custom"}),
#"Expanded Custom" = Table.ExpandTableColumn(#"Removed Other Columns", "Custom", {"Column1", "Column2", "Column3"}, {"Column1", "Column2", "Column3"}),
#"Promoted Headers" = Table.PromoteHeaders(#"Expanded Custom", [PromoteAllScalars=true]),
#"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers",{{"Database_RecID", Int64.Type}, {"Index_Number", Int64.Type}, {"Support_Type", type text}})
in
#"Changed Type"

I've to input code in custom columns, I don't know how to do it without coding.