You can install Docker Desktop and then try running it via Docker.

To do so,

    # Run the following once
    mkdir cloud-image-utils
    cd cloud-image-utils
    echo FROM ubuntu > Dockerfile
    echo RUN apt update >> Dockerfile
    echo RUN DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends cloud-image-utils >> Dockerfile
    docker build -t cloud-image-utils .
    
    # Now, you will be able to run cloud-localds by running the following
    docker run -v $(pwd):/mnt cloud-image-utils cloud-localds -v --network-config=/mnt/network.cfg /mnt/ubuntu.img /mnt/cloud_init.cfg

cloud-localds also works on MacOS with a little patch. After all, it's a bash script.

    brew install cdrtools
    wget -O cloud-localds https://github.com/canonical/cloud-utils/raw/main/bin/cloud-localds
    sed -i 's/genisoimage/mkisofs/g' cloud-localds
    chmod +x cloud-localds