How do I add fonts, that are not in the Adobe Typekit??

I want to add fonts (e.g. TheSans) to InDesign - but they are not in the Adobe Typekit.

How do I add them?

I have tried to add them to my pc and tried to add them directly to the "font" folder in my adobe InDesign folder. But tehy are still not available in InDesign.

Please help!