Hello,
1- Sorry to say but right now the Theme itself doesn’t have the option available for the OTP Login. You might want to use a third party Plugin for that.
2- As you know the Order Processing or the Thank You page comes from WooCommerce by default, so right now there isn’t a separate option available for that. You might want to consult the WooCommerce Support in this regard if they have a way out for this.
Although, if you want to show Extra Content on the Thank You page something like this: https://woodmart.xtemos.com/theme-settings-tooltips/extra-content-for-thank-you-page.jpg
Then please navigate to the Dashboard > Theme Settings > Shop > Thank You > there you can find the option Extra content for “Thank you page” > there you can add the extra content that you want to show: https://snipboard.io/9lR7jT.jpg
Best Regards.