Digital Ocean requires a Droplet to be powered off before a snapshot can be created. The Create Snapshot action on Zapier has an option to power off the Droplet first, but it only waits 20 seconds for the shutdown to complete.
If your Droplet takes longer than 20 seconds to power off, you may receive the following error:
Droplet is currently on. Please power it off to run this event.
In that case, you'll need to use a multi-step Zap. First, power off the Droplet with a "Power Droplet On/Off" step, then add a delay step for 5 minutes. Finally, add the "Create Snapshot" step (without checking the "power off droplet" checkbox). The Droplet will be automatically powered back on after the snapshot is taken.
The New Snapshot trigger gets the 20 oldest snapshots, in order of creation date. So if there are more than 20 snapshots on the selected droplet, the Zap will not be able to successfully trigger on new snapshots.