I am having a very hard time understanding your documentation overall. One thing I am particularly curious about is something you mention in your Xlsx recipe blog here: [https://jsreport.net/learn/xlsx](link url)
You say there, "Another approach we recommend is to create the whole excel the first, upload it into jsreport and then only replace its data, which is simple."
However, there is no explanation of how to do this, or work with the uploaded file. I found in the Studio UI under 'xlsxTemplates' you can upload an Excel file from my local hard drive, but after that, I have no idea what to do. How do I access the file? What do I do to replace the data?