I need to validation zip code in order confirm page. Once customer entered shipping address zip code is matched our allowed shipping zone zip code list process the order else return the error message.
Note: I have create custom plugin. So need to do this process via this plugin.
The SwagVatIDValidation of shopware does something similar - it validates the vatid on several pages (registration, changing of adress in account, by login, ...). You can get it for free in the community store, perhaps this will help you to get an inspiration on how to do it yourself.
https://store.shopware.com/en/swag161736212188f/vat-id-validation.html