Microsoft only supports more recent versions of Word for add-ins:

• Office 365 provides the best experience for Word add-ins (this is subscription Word)
• Word 2019 and later support all add-in features (this is purchased Word)
• Word 2016 is partially supported (some features are not available)
• Word earlier than Word 2016 is not supported

Our add-in works with both Windows and Mac computers, and no additional software is required for Mac.