This article discusses how to backup the APIGW. The data that needs to be backed up is the Docker volume used by the gateway container and the configuration directories on the host that are bind mounted to the containers.
The Docker volume named orbital-api-gateway_gateway-data should be backed up to prevent data loss. This Docker article explains how to backup a data volume.
The bind mount directories containing the configuration files are standard directories that can be backed up as desired. A simple approach would be to create a tar file of the contents. If /my/config is the bind mount directory on the host, then this can be done with the following command:
tar -czf gateway-backup.tgz /my/config