The menu built with the theme is dissociated from Elementor Pro so it wont work.

We have a lot of fonts (Google fonts ) available for the menu that you can change in WP-Admin > Theme Options > Menu Options

If you wish to use custom fonts, then you will have to do custom css.

Add custom fonts with Custom CSS:

a) Paste this code into Custom CSS field. This will tell your theme to load a custom font.

@font-face {    font-family: 'MyWebFont';    src: url('http://yoursite.com/fonts/webfont.eot'); / IE9 Compat Modes /    src: url('http://yoursite.com/fonts/webfont.eot?#iefix') format('embedded-opentype'), / IE6-IE8 /    url('http://yoursite.com/fonts/webfont.woff2') format('woff2'), / Super Modern Browsers /    url('http://yoursite.com/fonts/webfont.woff') format('woff'), / Pretty Modern Browsers /    url('http://yoursite.com/fonts/webfont.ttf') format('truetype'), / Safari, Android, iOS /    url('http://yoursite.com/fonts/webfont.svg#svgFontName') format('svg'); / Legacy iOS / }

Just put absolute paths to your font files. Note that you need to have different file formats since some browser will use only certain file type as explained here https://css-tricks.com/snippets/css/using-font-face/