Can't re-add headphones to Google Find Hub?

I have JBL Tune770NC headphones. I recently reported it as lost on the find hub, and found it. It continued to ping my friends' phones weeks later, so I decided to remove it from the Find Hub then re-add it.

However, I can't seem to be able to add it. There is no option anywhere to add a device to Find Hub. It worries me because I have already lost it once, and I want to be able to find it again.