
Explanation:

Box 1: "oauth2Permissions": ["login"]
oauth2Permissions specifies the collection of OAuth 2.0 permission scopes that the web API (resource) app exposes to client apps. These permission scopes may be granted to client apps during consent.
Box 2: "oauth2AllowImplicitFlow":true
For applications (Angular, Ember.js, React.js, and so on), Microsoft identity platform supports the OAuth 2.0 Implicit Grant flow.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/develop/reference-app-manifest