npm install error with discounts-reference-app/examples/react-router-app

I tried to clone and install the react-router-app example but got this error.

npm error code ERESOLVE
npm error ERESOLVE unable to resolve dependency tree
npm error
npm error While resolving: app@undefined
npm error Found: react-router@7.7.1
npm error node_modules/react-router
npm error react-router@"7.7.1" from the root project
npm error
npm error Could not resolve dependency:
npm error peer react-router@"^7.8.1" from @react-router/dev@7.8.1
npm error node_modules/@react-router/dev
npm error @react-router/dev@"7.8.1" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.
npm error
npm error
npm error For a full report see:
npm error /home/odmin/.npm/_logs/2025-10-11T22_33_39_523Z-eresolve-report.txt
npm error A complete log of this run can be found in: /home/odmin/.npm/_logs/2025-10-11T22_33_39_523Z-debug-0.log

Start by running npm install in discounts-reference-app/examples/react-router-app and inspect the declared react-router and @react-router/dev versions shown in the error. Confirm the dependency versions are compatible, then verify that a normal npm install completes without --force or --legacy-peer-deps.