- Add new field (textarea) in checkout.
- Add custom validation (text length) for this new field.
- Add new column in sales order grid page at admin.
- Display this note at sales order view page info at admin.
- give option to Add/edit note from admin.
- Save note with AJAX from admin.
- On Front end sales order view page display note to customer.
Referances:
https://webkul.com/blog/adding-additional-variables-in-window-checkoutconfig-on-magento-2-checkout-page/ https://devdocs.magento.com/guides/v2.4/ext-best-practices/tutorials/copy-fieldsets.html https://knockoutjs.com/documentation/extenders.html