I received a Schedule K-1 that has Box 16 checked (K-3 is attached) no Sch K-3 attached and the Instit that sent the document says the K3 sch will be avail by Aug 31, 22.

what do i do if i received a Schedule K-1 that has Box 16 checked (which means a schedule K-3 is attached) but there is no Schedule K-3 attached and the Institution that sent me the document says the K-3 schedule will be available by August 31, 22.