OSPF is different other than other routing protocols when it comes to advertise default route, how it is done ?

There are different area types in OSPF.

Stub areas, totally stubby areas and Not So Totally Stubby areas inject default route to summarize/filter prefixes.

Stub area will summarize Type5 LSAs as these are blocked in Stub areas.

Totally stubby area blocks Type3, Type4 and Type5 LSAs and will inject default route into the Totally Stubby Area.

Key thing here is to understand OSPF Area Types.

OSPF is use LSA TO advertise there is7 type for LSA