How to add Custom Font to your theme
In order to add custom font to your theme, you need to upload your custom font to the custom-fonts folder on your web server.
Go to \wp-content\themes\your_theme_name\assets\custom-fonts on your web server and create the folder named after your font and upload font ttf and/or woff and/or woff2 files to the folder.
Example - your folder structure should be like this for Great Sejagad font :
|- your_theme_folder |- custom-fonts |- Great Sejagad |- GreatSejagad.ttf |- GreatSejagad.woff2
Once you do this, The font will be visible in all select boxes throughout wp-admin just as default Google Fonts and you will be able to select it just as any other