@Terminator-Barbapapa Here is the initial version. I think this is quite of a progress in terms of design. On the final step, the user gets redirected to the upgrade page after he clicks the "Finish" button.

I think in the case of a multi checkbox option, replacing each checkbox with a toggle switch doesn't work well.

Let's only use a toggle switch for options that used to be a single checkbox. In the case of the 'Attach to' option I think we might want to move to an enhanced select option like we do for instance with the 'Disable for' setting. As you can see in my case I have a lot of potential emails the invoice can be attached to, creating a very long list.

@Terminator-Barbapapa I have added enhanced select.

I have deliberately added the following lines:

<link rel="stylesheet" href="<?php echo WC()->plugin_url() . '/assets/css/admin.css'; ?>">
<script src="<?php echo WC()->plugin_url() . '/assets/js/select2/select2.full.min.js'; ?>"></script>

because for some reason, wp_enqueue_style, wp_register_script, and wp_enqueue_style did not work for me.

With that, I am not sure why JS minifying is not working, I will try to reboot it.

@Terminator-Barbapapa I have added enhanced select.

I have deliberately added the following lines:

<link rel="stylesheet" href="<?php echo WC()->plugin_url() . '/assets/css/admin.css'; ?>">
<script src="<?php echo WC()->plugin_url() . '/assets/js/select2/select2.full.min.js'; ?>"></script>

because for some reason, wp_enqueue_style, wp_register_script, and wp_enqueue_style did not work for me.

With that, I am not sure why JS minifying is not working, I will try to reboot it.

@Terminator-Barbapapa Minifying is OK now.