What are the auth types that Adobe Sign support?

I work for a cloud signature provider, I saw in CSC documentation for different ways of auth types, external, TLS, basic, digest, oauth2code, and oauth2client find more at page 35
https://cloudsignatureconsortium.org/wp-content/uploads/2020/01/CSC_API_V1_1.0.4.0.pdf

I have some questions:
1. What are the auth types that Adobe Sign support?
2. How Adobe Sign system handle basic authentication?
3. Can the user instead of basic authentication use API tokens to login to service provider?

Thanks