We are implementing embedded document creation for our SaaS product. Some of our clients will be using their own accounts and credentials. Others may not have a DocuSign account and so will be able to set one up through us. How does a client authorize us to use their account credentials?
For example, say we want to create an authorization token to store on behalf of one our clients (i.e. post to ~/v2/oauth2/token). Would we pass our account's integrator key, with the client's username and password in the headers?