Adding procps helped me as well, thanks a million! My current config (as it differs from the one @Nexxado provided)
authorized_keys:
- >-
ssh-rsa
password: ""
apks:
- procps
server:
tcp_forwarding: true
sftp: false
compatibility_mode: false
allow_agent_forwarding: false
allow_remote_port_forwarding: true
allow_tcp_forwarding: true
zsh: true
share_sessions: false
init_commands: []