All the libraries use embedded icon fonts. In case you don’t see the icons in your wireframes, this just means, you still need to install or re-install the correct icon fonts locally or on a server online. This is easy and there is a good tutorial on Axure’s Forum (link or link) on how to install custom fonts. Just as a note; In case you want to install other fonts from Google or Apple, you need to go through a process called Font Mapping. See topic below.