VCSA 6.5 Backup (Permissions)

Hi, hope someone can point me in the right direction.

I will be backing up my VCSA 6.5 via HTTPS. As 6.5 does not have a scheduling solution out of the box, I am looking to use powershell running from a scheduled task. The way I see it, I can either call the REST API using Invoke-restMethod or I could use Get-CisServer. Where I am struggling to find a solution is, how to permission an account that has the least possible privileged to perform this action.

Using the cron option (Link below) from within the VCSA is not an option, I will fail all my security audits, unless someone can explain how I could not have the passwords exposed in plain text. And the configuration would need to be automated.

VMware vSphere 6.5 Documentation Library

Thanks