Hi,
You have saved your model as a .pth file. The next step is to load the trained model. For this, you do something like:
model=Net() ##Your model here
pre_trained_path="path.pth"   ##Your saved model path here
state_dict = torch.load(pre_trained_path)
model.load_state_dict(state_dict)
print(f'model {pre_trained_path} loaded')

Now, pass image as tensor to the model and get results:
with torch.no_grad():
       model.eval()
       result=model(input_image)

Hope that solves it