Can't retrieve mutations

[gianlucadonato]

If I query all the mutations available from the schema I got "mutationType": null.
This could means that we either don't have any mutation (and we should add them) or the schema is broken.

My feeling is the latter one, because no matter what I insert in the query I always receive the same result on the right, and seems like query filters are not applied. Also the docs error message suggest we have a problem in the schema.
See image attachment:

[stecb]

@gianlucadonato this is the default for any schema: you need to define what mutations you want