How to sync missing fonts?

[audras28065499]

I opened up an AI file on Illustrator, and it says the fonts in the document are missing, and it will not let me sync the appropriate ones. Any suggestions?

The fonts are HelveticaNeue-Thin & HelveticaNeue- Ultralight

Also, when I search these fonts up on Illustrator, they show up but they do not appear as they are supposed to, and have a pink background behind them.

[Test Screen Name]

The pink background confirms that the font is not installed on your computer. Where are you trying to sync the font from, and how?