Power BI with React using an existing workspace

We have successfully pulled in some Power BI dashboards via React into a simple page. We were able to do this by registering an app with Azure that we tied to a new workspace that we created. What we're trying to do now is use an existing workspace for this same purpose. The problem is we can't find any mention of the workspace id in the azure app. Is there a way to tie an azure app to an existing workspace in Power BI?