User has a Mac and is following instructions on this page - https://rally1.rallydev.com/slm/js-lib/excel-addin/get/#office365instructions. Per-user:
I am using Mac and Office 365 is installed. Please review the attached screenshots. As per step (6) "select the caret next to Manage My Add-ins and choose the Upload My Add-in option" mentioned here - https://rally1.rallydev.com/slm/js-lib/excel-addin/get/#office365instructions
There should be a caret next to Manage My Add-Ins. I don't see the caret and hence cannot Upload the manifest.xml file.
Component : MAC-OS: Excel 365
When uploading the Excel Plugin manifest.xml file in MAC to the directory (/Library/Containers/com.microsoft.Excel/Data/Documents/wef) please verify its location carefully, because the file location in Mac may show "Microsoft Excel" but in the details, it shows "com.microsoft.excel".
Note: Sometimes the Developer tab isn't displayed by default, but you can add it to the ribbon.
On the File tab, go to Options > Customize Ribbon.
Under Customize the Ribbon and under Main Tabs, select the Developer check box.
After you show the tab, the Developer tab stays visible, unless you clear the check box or have to reinstall a Microsoft Office program.