I assume you’re using the supplementary pages for this - is that right? If so, you don’t need to upload them each time, just once as a HTML Snippet and just attach them to the estimate/invoice each time. If you meant more of attaching them automatically, that’s not possible, although like many feature requests, we’re happy to consider this. It was previously mentioned elsewhere on the forums, but no feature request was created for this, so you may wish to start one.
You would firstly need a Yodlee subscription and then set it up following the instructions here. However, please let me know if you need further help.