Want to post adaptive card data to/from my website

anaas1070 - Webhooks are a great way for Teams to integrate with external apps. You can send Adaptive Card, Hero card, and text messages as attachment with Outgoing Webhook.

A webhook is essentially a POST request sent to a callback URL. In Teams, outgoing webhooks provide a simple way to allow users to send messages to your web service without having to go through the full process of creating bots via the Microsoft Bot Framework.
Reference Document:- Create an Outgoing Webhook - Teams | Microsoft Docs

https://github.com/OfficeDev/Microsoft-Teams-Samples/tree/main/samples/outgoing-webhook/csharp