All the (cisco) documentation I found about this topic always uses a DHCPv6 server or client to configure Prefix Delegation. But I never read that this is a requirement.
Can Prefix Delegation be configured without a DHCPv6 server or client?
Prefix delegation is a DHCPv6 option. You cannot do it without DHCP.
Here is the RFC: https://www.rfc-editor.org/rfc/rfc3633