wordpress-mime-type-upload-approve.php

/**
* Add that code to your theme functions.php file. Choose or modify which file/mime type need and delete the others.
* Replace the file type. More info: https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
* Gist by Tamas Rottenbacher
* Source: https://wpsmackdown.com/add-remove-filetypes-wordpress-media-library/
*/
function approve_mime_types($mime_types){
    $mime_types['rar'] = 'application/x-rar-compressed';  // Approve .rar file upload
    $mime_types['bmp'] = 'image/bmp';                     // Approve .bmp image upload
    $mime_types['svg'] = 'image/svg+xml';                 // Approve .svg image upload
    $mime_types['otf'] = 'application/x-font-otf';        // Approve .otf font upload
    $mime_types['ttf'] = 'application/x-font-ttf';        // Approve .ttf font upload
    $mime_types['woff'] = 'application/x-font-woff';      // Approve .woff font upload
    return $mime_types;
}

add_filter('upload_mimes', 'approve_mime_types', 1, 1);