I'm trying to develop a Office Add-In for Excel (n00b).
I have managed to do some things (creating tables and taking input and so on) when using Office.context.
But now I want to go into the different cells and all examples seems to run a method called Run on a object called Excel. (https://github.com/OfficeDev/office-js-docs/blob/master/excel/excel-add-ins-programming-overview.md)
However when trying to use Excel it's undefined. I am running Excel 2013. Can it be that I need to use 2016?
If you need JavaScript APIs that can work in Excel 2013, consult the original JavaScript API Reference pages.
The APIs you're asking about are only available in Office 2016 and later.
-Michael (PM for Office add-ins)