Launch Lambda function from Step function in different region

You're getting ResourceNotFound because Step Function is calling the Lambda endpoint in af-south-1 to invoke the Lambda function; but it isn't there (it's in `eu-west-1).

One way to solve this is to have a Lambda function in af-south-1 that is called by the Step Function and the only job of that Lambda function is to invoke the Lambda function in eu-west-1. However, having a Lambda function synchronously call another Lambda function is considered an anti-pattern: https://docs.aws.amazon.com/lambda/latest/operatorguide/functions-calling-functions.html