Select number of IPv6 Proxies that you want to create

When i add more than 1 i get an error example below

I also tried adding prefix like /64 /24 /128 at the end of it using digital ocean i just want to add tons of ports with the same ip

Error i get:

From IPv6 Address that has prefix 128 or no prefix set you may not generate more then 1 IPv6 Proxy, please change field Select number of IPv6 Proxies that you want to create to only 1