Missing ONNX Runtime Contrib Operators?

[probably-not]

I'm trying to run the pre-built Phi-3 ONNX Optimized models that are found on HuggingFace here: https://huggingface.co/microsoft/Phi-3-mini-128k-instruct-onnx.

They have pre-built ONNX models that are runnable on CPUs in their repo, but when I try to load it in Ortex, I get the following error:

iex(1)> Ortex.load("phi-3-onnx/cpu_and_mobile/cpu-int4-rtn-block-32-acc-level-4/phi3-mini-128k-instruct-cpu-int4-rtn-block-32-acc-level-4.onnx")
** (RuntimeError) Failed to create ONNX Runtime session: Load model from phi-3-onnx/cpu_and_mobile/cpu-int4-rtn-block-32-acc-level-4/phi3-mini-128k-instruct-cpu-int4-rtn-block-32-acc-level-4.onnx failed:Fatal error: com.microsoft:MatMulNBits(-1) is not a registered function/op
    (ortex 0.1.9) lib/ortex/model.ex:28: Ortex.Model.load/3
    iex:1: (file)

I do see that this specific operator is listed under the ONNX Runtime Contrib Operators: https://github.com/microsoft/onnxruntime/blob/main/docs/ContribOperators.md#com.microsoft.MatMulNBits.

I'm by no means anywhere close to an expert on these things, so I'm not sure if this is related to building a new Execution Provider (do I need to build the runtime with all of the contrib operators?), or if this is related to the ORT bindings (maybe they need to be updated?).