Thanks @alzhao, I was able to install extroot, mount a USB drive, and successfully install dockerd and luci-app-dockerman. However, I couldn’t get docker-compose installed. Error message:

Collected errors:
 * pkg_hash_check_unresolved: cannot find dependency python3-cryptography for python3-paramiko
 * pkg_hash_fetch_best_installation_candidate: Packages for python3-paramiko found, but incompatible with the architectures configured
 * satisfy_dependencies_for: Cannot satisfy the following dependencies for docker-compose:
 * 	python3-cryptography
 * opkg_install_cmd: Cannot install package docker-compose.

Any chance this could be made available as that is how I configure docker apps. Thank you.