I tried the dicom processing on an Ubuntu 22.04.2 machine (in case some subtle difference in the Mac's implementation of Bash or docker was responsible).  However, I see the same problem: The dcm directory is created but empty:

[dema:219 () 1139] $ /data/mri_reface/code/mri_reface_docker/run_mri_reface_docker.sh  T1_mprage_1mm_13 out -imType T1
You provided a directory for an input, rather than a nii file. We will assume it contains DICOM for a single series. Using the -imType flag is highly recommended with this workflow.
Running dcm2niix to convert to nii
Chris Rorden's dcm2niiX version v1.0.20230411  (JP2:OpenJPEG) (JP-LS:CharLS) GCC8.4.0 x86-64 (64-bit Linux)
Found 176 DICOM file(s)
Convert 176 DICOM as /tmp/tmp.8EJP90LOFN/T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13 (256x256x176x1)
Conversion required 0.087747 seconds (0.087351 for core code).
'/tmp/tmp.8EJP90LOFN/T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13.nii' -> '/var/tmp/tmp.f8OpIJxbk0/outputs/T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13.nii'
-------------------------------------------------------
Running mri_reface, version 0.3.2
By: Christopher G. Schwarz schwarz.christopher@mayo.edu
Temp directory: /tmp/tp23bd9256_ce04_40d4_a0bf_29a3a0d86f6c
Target file: /tmp/tmp.8EJP90LOFN/T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13.nii
Output directory: /var/tmp/tmp.f8OpIJxbk0/outputs
Target image type: T1
Template: /root/.mcrCache9.12/mri_re0/mri_reface/images/MCALT_FaceTemplate_T1.nii
Face atlas: /root/.mcrCache9.12/mri_re0/mri_reface/images/MCALT_FaceMask.nii

Calculating affine parameters to template. This will take some time.
Using face-optimized affine.
Estimating warp to template using ANTS. This will take a while.
Transforming images to input space using antsApplyTransforms
Finding face regions using the atlas
Matching intensities of warped-template to input (DBC)
Adding Rician noise to template to match noise levels in input image, with multiplier 1
Estimated noise PSF: 0
Noise in target image norm region: 6.187167 (2.791533%)
Noise in template image norm region: 2.160575 (0.974810%)
Noise to add: 5.797668 (2.615798%)
Noise in target image air: 0.440074 (16.009274%)
Noise in template image air: 0.027489 (1.000019%)
Noise to add in air: 0.439215 (210.910828%))
Replacing face
Replacing air
Saving outputs
Saved: T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13_deFaced.nii
Generating renders for QC use
Saved: T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13.png
Saved: T1_mprage_1mm_13_T1_mprage_1mm_20180706110327_13_deFaced.png
ADIR_ReFace finished in: 9.0485 minutes
Traceback (most recent call last):
  File "/usr/bin/mlrtapp/ADIR_nii2dicom", line 72, in <module>
    nii2dicom(args['<nii>'], args['<outDir>'], args['<originalDicomDir>'],verbose=args.get('--verbose',False),sliceDim=int(args.get('--sliceDim')),modality_default=str(args.get('--modality')),manufacturer_default=str(args.get('--manufacturer')),photometric_default=str(args.get('--photometric')),dry_run=args.get('--dry-run',False),uid_root=str(args.get('--UID_ROOT')),seriesNUM_select=args.get('--seriesNUM_select',None),seriesUID_select=args.get('--seriesUID_select',None))
  File "/usr/bin/mlrtapp/image_handling/ADIR_nii2dicom.py", line 110, in nii2dicom
    dicom_0 = dicom.dcmread(gzip.open(dcmfiles[0],mode='rb')) if(dcmfiles[0][-3:] == '.gz') else dicom.dcmread(dcmfiles[0])
IndexError: list index out of range
DICOM file directory is empty.
De-faced DICOM was written to /var/tmp/tmp.f8OpIJxbk0/outputs/dcm. This DICOM metadata is NOT otherwise de-identified. Only de-facing was performed. If you need the meta-data de-identified also, you should run it through your preferred DICOM de-identification software.
[dema:219 () 1140] $