Signing in BILLmanager

[HostingRising]

Do you have any guides describing authentication methods in BILLmanager?
I want my site users to sign in the billing system automatically.

[ksenya]

You can read some general information there (https://doc.ispsystem.com/index.php/Integration_between_BILLmanager_and_website)and there (https://doc.ispsystem.com/index.php/Working_with_ISPsystem%27s_API), and send us your questions