'Mapper' does not contain a definition for 'Initialize'

[cseas]

This error is thrown in the below code snippet for Startup.cs:

private static void InitializeMapper()
{
    Mapper.Initialize(x =>
    {
        x.CreateMap<Guest, GuestModel>();
        x.CreateMap<Room, RoomModel>();
        x.CreateMap<Reservation, ReservationModel>();
    });
}

This is probably because Mapper.Initialize is obsolete since version v9.0.0.