RHDH is currently only available for amd64/x86_64.
If you want an image that runs on Mac M1 (arm64/aarch64) or another architecture, you will need to build it yourself.
Check out this repo, choose the branch or tag you want to use, then build an image:
podman build -f docker/Dockerfile . -t redhat-developer/rhdh:localDownstream dockerfile and configuration can be found here:
Downstream sources use the above folder to transform sources in this repo to something that can be built within the Red Hat build pipeline.
Red Hat VPN access required.
For more info on building downstream with the Red Hat build pipeline, see the docs.