Most likely you are doing a GET on that creationFactory (I am guessing since I see input from a browser). For a creation you need to do a POST. and for that , you need to use applications like Postman. Plus, you need to send the resource you are creating in the body.
Otherwise, can I suggest you use the OSLC Reference Implementation (GitHub - oslc-op/refimpl) instead of the sample adaptors? The sample adaptors are just to simple, and have not been updated for a while.
In the refernce implementation, you can also see how a client is used to call the creation factory.