import { buildClient } from '@datocms/cma-client-node';
async function run() {
  const client = buildClient({ apiToken: '<YOUR_API_TOKEN>' });
  
  const siteInvitationId = '312';
  
  const siteInvitation = await client.siteInvitations.update(siteInvitationId, {
    role: {
      type: 'role',
      id: '34'
    }
  });
  
  console.log(siteInvitation);
}
run();

{
  id: '312',
  email: 'mark.smith@example.com',
  expired: 'mark.smith@example.com',
  invitation_link: 'https://dashboard.datocms.com/join-site?email=my-email%40datocms.comff&id=43796&preference=signup&token=xxx',
  role: {
    type: 'role',
    id: '34'
  }
}