Yes. You can use the license on any device. The limits are:
1000 request / 3 minutes if you whitelist the IP. You can whitelist up to 2 IPs. 100 request / 3 minutes limit applies if the IP isn't whitelisted.
(Correct me if I'm wrong) Perfect Canvas requests are one at a time, so both of you can't request Perfect Canvas Fingerprints at the same time. With Perfect Canvas, you're bound to hit the queue. So if you're working with Perfect Canvas, I suggest your friend gets his own key.
More info:
https://fingerprints.bablosoft.com/#pricing
https://wiki.bablosoft.com/doku.php?id=perfectcanvas (Limitations + FAQ)
