Fixed Server interface for Model execution

import SGPClient from 'sgp';

const client = new SGPClient({
  apiKey: process.env['SGP_API_KEY'], // This is the default and can be omitted
});

async function main() {
  const genericModelResponse = await client.modelServers.execute('model_server_id');

  console.log(genericModelResponse.error_message);
}

main();

{
  "status": "<string>",
  "status_code": 123,
  "error_message": "<string>"
}