backstage/.changeset/brave-eels-allow.md

@backstage/core-app-api

@backstage/core-app-api
minor

Updated the React Router wiring to make use of the new basename property of the router components in React Router v6 stable. To implement this, a new optional basename property has been added to the Router app component, which can be forwarded to the concrete router implementation in order to support this new behavior. This is done by default in any app that does not have a Router component override.