Hello Jimmy
A link-local address is always assigned to an IPv6 interface by the very design of IPv6. The purpose of the link-local address is so that an IPv6 host (PC, router interface, IP camera, TV, mobile phone, etc) can obtain network connectivity without any configuration needed. Processes such as Network Discovery Protocol (NDP) which enable such connectivity rely on the link-local address for this purpose.
For routers, the link-local address is the only IPv6 address that is necessary on an interface. The next-hop IP address provided in the IPv6 routing table is almost always the link-local address (along with the exit interface), even though the unique global address can also be used for this purpose. IPv6 Routing protocols such as OSPFv3 and EIGRP and others, use the link-local addresses to exchange information and create neighbor adjacencies.
You can find out more about the link-local address as well as the processes that require it to function at the following lessons:
I hope this has been helpful!
Laz