First thing first...
You need to know why you are getting the error in the first place.
Lets take a simple HttpPost of JSON Data that looks like this:
{
"conversationID": 1,
"senderUserID": 1,
"receiverUserID": 2,
"message": "I fell for the wrong man!",
"created":"2022-02-14T21:18:11.186Z"
}
If you generated your database using Entity framework core while connecting to SQLServer or any other database server, the database automatically takes the responsibility of updating and auto-generating the Key/Unique identifier of the Identity Column, which in most cases is an integer value it auto-increments.
To safely post your data using the in-built conventions which keeps you at a safer end, just remove the ID field from the data you want to send to the database, and let the database engine and ef-core do the heavy lifting which they are designed to do.
So the proper way to post the data would be:
{
"senderUserID": 1,
"receiverUserID": 2,
"message": "I fell for the wrong man!",
"created":"2022-02-14T21:18:11.186Z"
}
You would notice I took out the ConversationID.
You can learn more about entity framework on this website : https://entityframeworkcore.com
I hope you stick more to conventions than configuration in your apps. Knowing how to do things with already proven standards and conventions will save you a lot of working hours.