Paginated results from an API in Power Query

Are you referrring to: Table.GenerateByPage?

I've tried using this, but power query says the expression is unrecognised.

I looked at this page: Helper functions for M extensions for Power Query connectors - Power Query | Microsoft Learn - which says at the top that it's not part of the laibrary yet and needs to be copied.

I managed to get as far as createing this code, which resulted in a row 201 appearing, but with an error, which was progress of a sort: 

let
    // Define the Table.GenerateByPage function for pagination
    Table.GenerateByPage = (getNextPage as function) as table =>
    let        
        listOfPages = List.Generate(
            () => getNextPage(null),            // Get the first page of data
            (lastPage) => lastPage <> null,     // Stop when the function returns null
            (lastPage) => getNextPage(lastPage) // Pass the previous page to the next function call
        ),
        // Concatenate the pages together
        tableOfPages = Table.FromList(listOfPages, Splitter.SplitByNothing(), {"Column1"}),
        firstRow = tableOfPages{0}?
    in
        // If we didn't get back any pages of data, return an empty table
        // Otherwise set the table type based on the columns of the first page
        if (firstRow = null) then
            Table.FromRows({})
        else if (Table.IsEmpty(firstRow[Column1])) then
            firstRow[Column1]
        else
            Value.ReplaceType(
                Table.ExpandTableColumn(tableOfPages, "Column1", Table.ColumnNames(firstRow[Column1])),
                Value.Type(firstRow[Column1])
            ),

    // Define the getNextPage function for your API
    getNextPage = (lastPage as nullable any) =>
    let
        // Construct the API URL with pagination logic
        url = "https://finder.bloodsandbeyond.co.uk/myURL" & 
              (if lastPage = null then "" else "?$skip=" & Number.ToText(lastPage)),
        headers = [
            #"x-api-token" = "?????????????????"
        ],
        source = Web.Contents(url, [Headers=headers]),
        jsonResponse = Json.Document(source),
        value = jsonResponse[value],
        // Check if the value is null or empty
        nextPage = if value = null or List.IsEmpty(value) then null else value
    in
        // Return the result as a table or null
        if nextPage = null then null else Table.FromList(nextPage, Splitter.SplitByNothing(), null, null, ExtraValues.Error),

    // Use Table.GenerateByPage to get all data
    allData = Table.GenerateByPage(getNextPage)
in
    allData

When I expand the error, it was:
Expression.Error: We cannot convert a value of type Table to type Number.
Details:
Value=[Table]
Type=[Type]#

I'm guessing some part of this code tries to covert a table to a number, but I don't know enough about it to decipher it. Chat GPT disappeared up it's own tail trying to work out a fix. I'm optimistically hoping that someone smart enough can see the code and it's a simple fix. I feel like I'm really close.