Does Source Connector requires output.schema.value to be specified with Avro/Json

Hello Mongo Team,

I am creating a source connector and my connector is giving me the below error if i donot provide output.schema.value in avro format , while trying to configure through confluent cli.

Can we not specify the schema to the topic manually through cli without providing the schema definition through output.schema.value property ?

Below is my config for your reference :

{
  "name": "mongodb-source-carrier360-auto-assignment-connector",
  "config": {
    "producer.sasl.jaas.config": "org.apache.kafka.common.security.plain.PlainLoginModule required username='XXXX' password='XXXX",
    "key.converter.schema.enable": "false",
    "value.converter.schema.registry.basic.auth.user.info": "XXXXX",
    "errors.deadletterqueue.context.headers.enable": "true",
    "value.converter.basic.auth.credentials.source": "USER_INFO",
    "sasl.mechanism": "SASL_SSL",
    "producer.security.protocol": "SASL_SSL",
    "topics": "AutomationRules_DEV.CarrierAutoAssignment",
    "security.protocol": "SASL_PLAINTEXT",
    "value.converter.schema.registry.url": "XXXXX",
    "key.converter.schema.registry.url": "XXXXX",
    "name": "mongodb-source-carrier360-auto-assignment-connector",
    "connector.class": "com.mongodb.kafka.connect.MongoSourceConnector",
    "tasks.max": "1",
    "key.converter": "org.apache.kafka.connect.storage.StringConverter",
    "value.converter": "io.confluent.connect.protobuf.ProtobufConverter",
    "transforms": "RemoveString, WrapKey",
    "errors.log.enable": "true",
    "errors.log.include.messages": "true",
    "transforms.RemoveString.type": "org.apache.kafka.connect.transforms.RegexRouter",
    "transforms.RemoveString.regex": "AutomationRules_DEV.CarrierAutoAssignment",
    "transforms.RemoveString.replacement": "CARRIER360-AUTO-ASSIGNMENT",
    "transforms.WrapKey.type": "org.apache.kafka.connect.transforms.HoistField$Key",
    "transforms.WrapKey.field": "_id",
    "connection.uri": "mongodb+srv://<>:<>@<>/AutomationRules_DEV?authSource=%24external&authMechanism=PLAIN&retryWrites=true&w=majority",
    "database": "AutomationRules_DEV",
    "collection": "CarrierAutoAssignment",
    "publish.full.document.only": "true",
    "mongo.errors.tolerance": "all",
    "mongo.errors.log.enable": "true",
    "errors.deadletterqueue.topic.name": "ERROR.TOPIC"
  }
}
Error encountered in task mongodb-source-carrier360-auto-assignment-connector-0. Executing stage 'VALUE_CONVERTER' with class 'io.confluent.connect.protobuf.ProtobufConverter', where source record is = SourceRecord{sourcePartition={n

java.lang.IllegalArgumentException: Unsupported root schema of type STRING
	at io.confluent.connect.protobuf.ProtobufData.rawSchemaFromConnectSchema(ProtobufData.java:627)