I want to use ExcelApi 1.2~ 1.5.
But When I check my ExcelApi version, This is 1.1.
How to upgrade my ExcelApi version?
If you are on O365 plan, you can get the latest Office version to use the new APIs. If you have the MSI version (Office-2016, but service patch updates only), then you'll have to upgrade to O365 (It appears that you have the MSI version looking at your version#. I can't be 100% sure). Excel online offers the latest version always.