How to export xlsx from a webgl webpage made with unity?

Honestly, unless you are prepared to post code here in Code Project, it’s very unlikely that anyone is going to help you. Posting random links to shortened URLs that could lead anywhere is not a way to gain trust. On top of that, I can’t imagine what you are trying to export here. Are you trying to paste screenshots into Excel? Source code? Whatever you are trying to do here, you need to stop and consider whether a spreadsheet is the correct choice.

Rather than randomly doing things, tell us what it is that you are trying to accomplish with this. What is your actual requirement? We are more much more likely to be able to help if you tell us what you are trying to actually do, and we may be able to suggest alternatives.