Hello,
Thanks for reaching Crowd support,
Kindly notice that to install the Zerotier package from CLI you can type:
#opkg update
#opkg install zerotier
Or else you can use the WebUI interface to download the package :
Go to Services --> Package manager --> Search for Zerotier from the pages --> hit the + button under the Actions section, and wait for some time and it will be done.
You can find the Zerotier under the Services --> VPN section on the WebUI page.
If you need any further help don't hesitate to contact us again.
Regards.
Bader Kh.