Hi there,
You can not add the additional weights to the Font Manager by default. You need to customize the theme by adding the code below to the functions.php file of your Child Theme:
/**
* Enqueue scripts and styles.
*/
add_action( 'wp_enqueue_scripts', 'load_scripts' );
function load_scripts() {
wp_enqueue_style( 'fns-google-font', 'https://fonts.googleapis.com/css?family=Montserrat:200i,300,300i,400,500i,600,600i' );
}
The sample code above adds more weights, you can change the code to have the ones you like.
After that, you will need to use custom CSS to force the weight you like and you can not use the options available in different sections of the theme. For example, to change the weight of the h2 tag you will need to add the CSS code below to X > Launch > Options > CSS:
h2 {
font-weight: 300;
}
Thank you.