Your login isn't the owner of this community site. Log in with the account you used to create it in "My Community Site."
Choose how the "Homes for Sale" section on your public page finds listings.
In NTREIS Matrix, go to My Matrix > Settings > IDX Configuration, open (or create) an IDX page, and copy the full code from the HTML field under Activation. Paste the whole thing below — no need to edit it first.
Preview — this is what visitors will see: