There are two primary ways to integrate MathType into Word 2013:

If your version of Word 2013 supports the Office Store, you can add it directly: How To Integrate Math Type With Microsoft Office Word 2013

To download and use MathType with Microsoft Word 2013, you can use the official installer provided by Wiris or install it as an add-in directly within the application. While older versions like MathType 6.9 were designed for Office 2013, they are now deprecated, and it is recommended to use the latest version for compatibility and security.