How can I do this.
When the customer has not paid.
This was possible during the http days. It was done as follows:
With Https this cannot be done anymore.
It is sad because it was handy back then and simple.
Notifications feature could replace this functionality by sending an automated email/sms/whatsapp/or push notifocation when the account is about to expire, and when it expires with a link to the client portal for more information
How can this be done?
(There are billing systems that have web notification.)