Error: DynamoDB No Regionendpoint Or Serviceurl Configured

The AWS SDK for .NET has no Region or service endpoint for the DynamoDB client. For an AWS-hosted table, configure the Region containing the table; for DynamoDB Local, configure its endpoint URL.

using Amazon;
using Amazon.DynamoDBv2;

using var client = new AmazonDynamoDBClient(
    new AmazonDynamoDBConfig { RegionEndpoint = RegionEndpoint.EUWest1 });

This example uses the SDK credential provider chain. Credentials and the endpoint are separate settings: supplying one does not supply the other. For Local, use ServiceURL = "http://localhost:8000" and local-only signing credentials in your development configuration.

See DynamoDB with .NET and the AWS SDK for .NET Region guide.