Buyers who are represented by an agent cannot submit offers on their own. To do so would create confusion. This is why the button says "Simulated Offer - Please Contact Your Agent" instead of "Confirm Offer" which is what agents and buyers without agents would see.
However, such buyers can view and simulate new offers and changes to existing offers. To do this, they would enter terms and see the rank and order of their simulated offer. If an offer was already offered by the agent, find it among the bids on the left side and simply click on it. The details of the offer submitted by your agent will be shown on the left side.
If you had connected with an agent incorrectly, you can contact Snapdoor at firstname.lastname@example.org and asked that the connection be undone.