Find proof of purchase (PO, etc) and email the info to Apple. they'll unlock it for you.

@CasperSally Sure I could do that thank you. I'd like to figure out with this device is unsupervised as well as 25 other devices in my JSS and how I can get them supervised so I don't run into this in the future.

@TomDay if the device was setup before it was added to DEP then you could run into the situation you've run into. We're in the same situation as you are with a portion of our iPads. We had setup and enrolled many devices before the DEP program came out. The only way I know of fixing the supervision issue, is to wipe the device and re-setup the device from scratch using a DEP PreStage Enrollment. I think if you try restoring an iCloud backup created of the unsupervised iPad back to the same device it will leave it unsupervised even if you started the enrollment from a DEP PreStage Enrollment. I think you can restore an iCloud backup created of an unsupervised device to a different device using a DEP PreStage Enrollment and have the device supervised at the end of the process. But I might be wrong on that point.

@mpermann After some further digging into my JSS, you are exactly right. This was a device that we had enrolled OTA, before DEP. The vast majority of my devices have been wiped and re-enrolled post-DEP so that is why they have Activation Lock Bypass enabled. I spoke with Jamf support, nothing I can do for the last few devices that are not supervised other than wiping and re-enrolling.