Access Management

I remember there is some information around that topic in here (maybe FAQs)

I am using this code snippet to allow only specific users to access it. Per default every Editor can access Simple History.

<?php 

// Allow only the users specified in $allowed_users to show the history page, the history widget on the dashboard, or the history settings page
add_filter( 'simple_history/show_dashboard_page', 'function_show_history_dashboard_or_page' );
add_filter( 'simple_history/show_dashboard_widget', 'function_show_history_dashboard_or_page' );
add_filter( 'simple_history/show_settings_page', 'function_show_history_dashboard_or_page' );
add_filter( 'simple_history/add_admin_bar_menu_item', 'function_show_history_dashboard_or_page' );
add_filter( 'simple_history/add_admin_bar_network_menu_item', 'function_show_history_dashboard_or_page' );

function function_show_history_dashboard_or_page( $show ) {
    $allowed_users = array(
        'theindividualeditorusername',
    );

    $user = wp_get_current_user();

    if ( ! in_array( $user->user_login, $allowed_users ) ) {
        $show = false;
    }

    return $show;
}

Thanks for the snippet @markussss!