can i run it on an agent that doesn't have gpu?

Sure this is fully supported

when i run clearml-serving it throughs me an error "please provide specific config.pbtxt definion"

Yes this is a small file that tells the Triton server how load the model:
Here is an example:
https://github.com/triton-inference-server/server/blob/main/docs/examples/model_repository/inception_graphdef/config.pbtxt