Register dynamic protobuf schemas in kafka schema registry generally

I implemented many pipelines that produce proto typed data to kafka. I want to see if there is a general way to register every proto file that uses different schema with the same function without converting proto message to corresponding java object such as using complier:

  protoc -I=. --java_out=. my_proto.proto

In another words, is there any way to register schema only via .proto file just like registering the avro format via avsc file but that with json format?

There is not. The Schema Registry has a well-defined JSON-based API, and does not accept other schema formats.

https://docs.confluent.io/platform/current/schema-registry/develop/api.html

You could try using the Registry maven plugin, though. Otherwise, you need to write your own script to JSONify the proto schema into a payload the registry accepts (keep in mind, this happens automatically when you use ProtobufSerializer from Confluent)