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The link given above links you directly to the home page of the prototype. From there, you can use the prototype's navigation buttons (add transaction, view transactions, settings) at the bottom to access and reach any portion of the site that you wish to visit. Remember, the prototype is canned, and there is currently no backend support, so please do not be surprised if you reach an unimplemented page. In terms of viewing the transactions between you and another user, you want to only look at the history between you and "Karen Doe" as her page is fully implemented.