A barcode or bar code is a way of presenting data in a visual, machine-readable form. Generally speaking, barcode is an image of rectangular form that consists of parallel black lines and white spaces of different widths. Barcodes are used in various areas where quick identification is necessary - as part of the purchase process in retail stores, in warehouses to track inventory, and on invoices to assist in accounting, among many other uses....Please get your Client Id and Client Secret from https://dashboard...place Client Id in "client_id" and Client Secret in "client_secret"...