Asking for help: missing Crop file (NKI dataset)

Hi everyone,
That is my first post, I’m quite new in the field.
In order to discover and practice the BIDS, I followed the tutorial. I downloaded the NKI dataset and did the steps to convert the data from DICOM to NIFTI. It’s fine until the second stage of step 5.
I downloaded MRIcroGC and did all the steps through conversion. But once the conversation is over, I have 2 files, not 3.
The first one is the XXX_MPRAGE.json (as expected) and the second one is the XXXX_MPRAGE.nii.gz. So I 7zipped it to have the .nii file.
First question: is it correct to extract files from gz (step not mentioned in the tutorial)?

And my main problem is I don’t have a XXX_Crop_1.nii no matter how many times I do the operation again. I read the bids_specs documentation but I could’nt find the answer.
I tried to do the validation step but it’s incorrect.
I do not have a lot of expertise in the field so I’m not sure what happened and how to solve it.
If you have advice or answers, I would love to read them!
Thank you.

Hi, to create the crop file, when you convert the images (Dicom to nii) you have to select the “crop 3D images” option in the MRIcro Gui.