how can we connect external vertex server by using trustedID concept instead of username and passwor

we had a problem when we tried to implement CyberArk(security mechanism) for the integration of vertex(TAX calculation) and PeopleSoft. currently we are having username and password method to connect to vertex for tax calculation by using integration broker. but vertex team suggested us to use trustedID method to connect them instead of CyberArk. we are not sure about that trustedID concept, please provide a direction to achieve that to do improve our security. They have mentioned in vertex-pgc-properties file more clarity on this.