See this blog post by Simon Richert on the Power BI Community site on how to take over Goal connections for a Scorecard using Powershell.
Run this script to bulk update goal connections in a given scorecard to use your own identity during query refresh. This is especially useful when a user is no longer present in the directory or somehow loses access to source datasets, leaving a lot of stale goal connections behind. We’re working on bringing the “take over” functionality directly to the goals UI, but you might find this script handy in the meanwhile.
Power BI Goals Pro Tip: Take over goal connections… – Microsoft Power BI Community