What pay plan should I use if I want to use my own resources?

My case is I want to use my own adobe-sign document resources. So, I can send my document  to users, then they can sign it.

I write a demo using adobe-sign restful api, here is the github repo url address: GitHub - mrdulin/adobe-sign: adobe sign research

But, this demo is User application, the workflow is user login -> authorization -> my app can use user's resources.

I want is: me as the administrator -> send my own resources to user.

Don't want to user open the authorization url in browser.  I want use my own node.js service to get my resources and send to user.

I found the pay plans here: Adobe Sign plans for individuals and businesses | Adobe Document Cloud

What plans should I use? Is "Individual" plans enough?