https://www.digitalocean.com/docs/networking/ipv6/
Yes, you read that right, they assign a /124 if you enable IPv6. There is no provision for getting anything larger. All configuration is totally static as well. It's really incredible how botched the setup is, and it has been like this for years.
If you're wondering if you're sharing the same /64 with an entire datacenter worth of droplets, the answer is of course.
I haven't contacted them about it but that makes sense sadly. So they're getting a /64 from their upstream and just sharing that out to everyone. This isn't IPv4, they need to make this right.
Vultr, OTOH, gives each HOST a /64. I've been doing most of my work on Vultr right now so I can use more than 16 IPs on a single host. I was/am hoping that providers would standardize somewhere in the middle: Every customer account in each datacenter gets a /64. I wouldn't mind all of my hosts having their own /64 to subdivide.
It's not like it is hard to get IPv6 address space either. All they have to do is ask. A VPS provider like DO can get a /32 easy peasy.
(And a /48 from APNIC???)
(Edit: And a /36, /40 and /48 from APNIC?)