Edit labels of DICOM images

I haved used Monailabel to label my images. I need to edit the labeling but have problems loading the labels on top of the image. This is how it looks like when I press “Submit Label”

When I load the label it looks like this. How can I edit it?

Background:
I started out with DICOM images which I transformed into NifTi images stored as .dcm.nii.gz. I think that causes some problems. At least the “Next Sample” button does not work. I have to drag the images into 3Dslicer.

I have used the Segmentation configuration from the radiology app. Should I have used the deepgrow or something else?

Solved!
I got lost in MonaiLabel which wasn’t actually necessary for my purpose. Also, I got confused with the differences between volumes and segmentations.

This tutorial was helpful: https://www.youtube.com/watch?v=xIts_5fctYg
and this forum question: How to edit nii.gz file that was created using another program?