Upgrading shinyapps.io service from free to paid

Hello,
Our organization is using free membership to shinyapps.io since last few months.
We like the functionality.
So want to upgrade the service.

We are a tech startup from India.Which professional plan will provide user authentication?
Means users should be able to access our app after successfully login.They should be able to create new user account and passwords for themselves.

Is this functionality built in available?If not will we get any guidance?

Also how can we keep track of user activity?
If we want to restrict access to only few devices is it possible to do that with upgraded plan?

We want strict confidentiality & authenticity ?

Also active hours limit can we change?

Please answer all these questions.
Thanks.
Rupali


This question it's been duplicated on this other topic