Id element
Specifies the unique ID of your Office Add-in as a GUID. Use a random GUID generating tool to get your GUID. The GUID should be hyphenated, but have no other punctuation.
Add-in type: Content, Task pane, Mail
Syntax
<Id>string</Id>
Specifies the unique ID of your Office Add-in as a GUID. Use a random GUID generating tool to get your GUID. The GUID should be hyphenated, but have no other punctuation.
Add-in type: Content, Task pane, Mail
<Id>string</Id>