Easy Digital Downloads - Front-End Submissions - Allow only specific mime types upload

functions.php

// FES form field name : Prices and Files

add_filter( 'upload_mimes', 'dcg_restrict_mime_types', 1, 1 );
function dcg_restrict_mime_types( $mime_types )
{
    
    $user = wp_get_current_user(); // get the current user
    // if user is shop vendor or a shop manager
    if ( in_array( 'shop_vendor', (array) $user->roles ) || in_array( 'shop_manager', (array) $user->roles ) ) {
        
        // add the mime types you want to allow to upload
        $mime_types = array(
            'zip' => 'application/zip',
        );
        
        // Use unset to remove specific mime types uploads.
        // unset( $mime_types['xls'] );  // Remove .xls extension
        // unset( $mime_types['xlsx'] ); // Remove .xlsx extension
        // unset( $mime_types['docx'] ); // Remove .docx extension
    
        return $mime_types;
    }
}