model_pt_path = "test_1.onnx"
data_1 = torch.randn(23, 64)
hidden_1 = torch.randn(1, 64, 850)
output = torch.onnx.export(model, (data_1, hidden_1), model_onnx_path, verbose=True)

I added code above to try to export the model, thanks a lot!