Thank you for your interest. Our container images only support the "amd64" architecture as you can see in dockerhub
That means that they are not supported in a Raspberry machine as it has ARM. You'll need to find alternative Moodle containers to deploy the app there or build one by your own.
If you have any other question about the Bitnami Moodle container, we provide technical support for it in our Github repository for Moodle
You only need to open a new "issue" there and our team will take care of it.