You can copy and paste the following submit file; name the file example.submit to go along with the recipes. It needs the busybox.sif file to run; see below.

universe                = container
# singularity pull busybox.sif docker://busybox:latest
container_image         = busybox.sif
executable              = /bin/sleep
arguments               = 1200

should_transfer_files   = YES
output                  = example.output
error                   = example.err
log                     = example.log

queue 1

You can use singularity pull to obtain busybox.sif from Docker Hub; run this command in the same directory that you created the submit file in:

$ singularity pull busybox.sif docker://busybox:latest