Create an External Client App

I am learning trailhead "Create an External Client App" : https://trailhead.salesforce.com/content/learn/projects/create-an-external-client-app-using-metadata-api/create-an-external-client-app?trail_id=dive-deeper-into-salesforce-development-tools-and-concepts

and follow the step to create external client app, but when I tried to deploy the package.xml. I met the issue below:  

I didn't find any solution in google, Please help, thank you.