Set Up Your Development Environment for Legacy Packages
Install a Package Create an installed package in your Marketing Cloud account to create API integrations, install custom apps, or add custom Journey Builder components.
Get a Client ID and Secret To use the Marketing Cloud API, create an API integration. Creating an API integration gets you a client ID and secret.
Get an Access Token Use your client ID and secret credentials to get an OAuth access token directly from the requestToken API authentication service. Use the access token to authenticate subsequent calls.