Dropbox API v2, gateway credential error

Below is the correct answer using API v1 and OAUTH1 from user Masplin (Mike), not me.

But I tried this and it worked perfectly!

I have successful connected my desktop model to an anonnymous dropbox link and it refreshes absolutely fine on PBI servce. OneDrive is an absolute disaster as a cloud storage system, it works for Power bI but is garbagge for anything else.

The issue I have is where my query is doing a folder query so I need ot try Imke solution

For example I have this file Inputs.xlsx which sits in Dropbox\DataModels\SourceFiles.

firstly create a blank query to set the path to the file

DropboxSourcePath is

let
Source = "https://api-content.dropbox.com/1/files/auto/DataModel/SourceFiles/"
in
Source

Secondly go onto dropbox online and into developer section as Imke described ot create an app and get a token.  In my case I have tried her folder app so I just got a token for the whole of dropbox.

Token is

let
Source = "?access_token=lkPfa4vOd-AAAAAAAAAAKjmGh93HWPeYFfffdfffdfdggf-CY0LSTVss5JF53HOGK46xxkWsQzhj-"
in
Source

Then your query becomes. Note now web.contents instead of file.contents and if you have any path its "/" not "\"

let
Source = Excel.Workbook(Web.Contents(DropboxSourcePath & "Inputs.xlsx" & Token), null, true),
Seasonality_Table = Source{[Item="Seasonality",Kind="Table"]}[Data],
#"Changed Type" = Table.TransformColumnTypes(Seasonality_Table,{{"Month No", Int64.Type}, {"Month", type text}, {"Car Count Seasonality", type number}, {"GTV Seasonality", type number}})
in
#"Changed Type"

So I can refresh all conenctions on desktop and when I publish to PBI Service I see under credential web for each of these dropbox links. Edit conenction and chose annonymous.