WKND GraphQL React app

I have followed this link: https://experienceleague.adobe.com/docs/experience-manager-learn/getting-started-with-aem-headless/graphql/multi-step/graphql-and-external-app.html?lang=en to do the setup for GraphQL in AEM. To use the data generated from GraphQL queries, a react app is used. For that a git repository command is given in the documentation. That didn't work for me. So, I cloned this git repository: https://github.com/adobe/aem-guides-wknd-graphql and in that it is mentioned to run these commands in the react app folder :

npm install

npm start

But when I do this, the page is loaded but shows this error:

How to solve this error?