Dunno about gradient and they seem to want you to use their web console for shell sessions in general. You have to buy a public ip address ($3/m) and connect it to your instance to ssh in. I dunno if you can do that with gradient notebooks but I did it with a regular machine. After connecting the ip address, it didn’t work, I rebooted and it still didn’t work, but a couple minutes later it worked. So maybe some routing table had to update someplace after the first failure, or maybe I should have just waited a while, or whatever.
To log in after the ip works, ssh to paperspace@yourip and use the password that they email you. If you’re familiar with linux you might want to set up .ssh/authorized_keys so you don’t have to mess with the password (public/private key login). I ran my usual ansible script that I set up new servers with and it worked fine, even though it’s written for debian and paperspace only has ubuntu.