Dynamically Change date range of web source (api link)

AI14 Create a table in Excel with name DateParameter

And then you can load the table into PQ, the code will look like this:

let
    Source = 
        Excel.CurrentWorkbook(){[ Name = "DateParameter" ]}[Content],
    ChangedType = 
        Table.TransformColumnTypes ( Source, { { "Date", type datetime } } ),
    Date = 
        Date.ToText (
            Date.From ( ChangedType[Date]{0} ),
            [ Format = "yyyy-MM-dd", Culture = "en-US" ]
        )
in
    Date

As you can see the the data type of quer is just scalar text value now you can use the name DateParameter in your original code.