Can we define directives using Ratel?

From the tutorials present in https://dgraph.io/tour/schema/1/ and https://dgraph.io/tour/intro/3/ it seems that you cannot manually create a schema using the endpoint where Ratel runs. Is there a way to define types and directives in Ratel in the form of a query?

Not sure what you mean. Ratel and Tour are different things. The Tour has an endpoint for Alter operations and Ratel too. If you wanna do the Tour using Ratel it is totally possible.

No, query, mutations and Alter operations are different and have to run in their specific endpoints or method. But you can query for the Schema tho. In the Query operation, you can ask for the schema as a JSON response, but you can’t edit it via mutations.

If you go to the Ratel > Schema > “Bulk Edit” (small button in the top navigation of the schema) you can write new predicates and types in that dialog box and apply them to your server. Works exactly like the tour.
We removed Schema editing from the Ratel query pane when Schema & Types UI was launched. Maybe we should consider putting it back, because a few users asked about that.