How to enable https for wordpress and install certificate

Question

I have been able to create a custom endpoint following the code below for wordpress

function handle_woocommerce_keys($request){
    $user_id = $request[user_id];
    $consumer_key=$request[consumer_key];
    $consumer_secret=$request[consumer_secret];
    $key_permissions=$request[key_permissions];

/* search user_id in db and store the keys as meta_data */


    $response = new WP_REST_Response();
    $response->set_status(200);

    return $response;
}

add_action('rest_api_init', function () {
    register_rest_route( 'village/v1', 'authkeys',array(
        'methods'  => 'POST',
        'callback' => 'handle_woocommerce_keys'
    ));
});

Unfortunatly it's only working using HTTP. I use Postman and it behave has expected. However, I need HTTPS to be supported. The reason is that the endpoint URL is provide as param to a server and used by this server to send a POST to this https URL.

Any idea how to make HTTPS endpoint supported on Wordpress ?

Do I need to install a certificate, If yes how ? Thanks