403 error while calling Query from React

Called this function from React , server is running at the backend

  let user = await new Parse.Query('User')
    .equalTo("username", phone)

Received this error

How Do I resolve this?

Can you share how you are initializing the Parse SDK and double check if your have set the right keys?

My first guess would be that you’re not supplying your AppId. If you’re using the REST api, you need to pass the appId along with your request, using the Parse-Application-Id header.