To import a font into Illustrator, first open the File menu and select “Open With…” then select Illustrator. Then, under “Fonts” on the left, click on the “Fonts” button and select the font you want to import.
There are a few reasons why your fonts might not be showing up in Illustrator. One reason is that Illustrator does not support vector files. If you want to create vector files, you’ll need to use another software such as Inkscape or GIMP.