Lanrover/E Plus 5x & hunt group

I have two Lanrover/E Plus rack modems. Phone company says phone #’s are part of a hunt group (16 lines total). I can get only 1 line to answer a modem dial-in. Next caller rings forever with no answer. Can’t find any documentation on the product.Any ideas on how to properly set this up so that first caller gets in. Then next caller automatically rolls over to next modem and gets answered, etc. Help please! The callers are getting hostile!