Since you want to run a script on a daily schedule within a private network, you should use a Private Endpoint along with the Azure Automation account directly or consider deploying a Hybrid Runbook Worker if the script needs to interact with resources that are not directly accessible by the Automation Account.
here are some links those can help you
https://learn.microsoft.com/en-us/azure/automation/automation-private-link
https://learn.microsoft.com/en-us/azure/automation/automation-hybrid-runbook-worker