We have implemented something not a modernize way though 🙂 like using rest api's.
you can write down a powershell script for calling a runbook in automation account in your sub.
1. calling script will be placed in mid-server of service now and picks up the parameters from now and pass it to calling script, calling script will trigger runbook with parameters.
2. main script in runbook- will have the actual action using your parameters like user, type of client etc and performs provisioned, delete and maintaince.
you can do while do loop in calling script it self to get the output from the runbook and post in your servicenow request..
between you can use the logic apps or function apps as per your requirement.
