The DOM is a price ladder that sits as a tab beside the order ticket. It gives you a vertical view of prices with order entry attached, which suits scalping and fast management better than filling in the ticket each time.
Load a price into the ticket
Click a price on the ladder and it loads into the order ticket. From there you can adjust and send as normal, so the ladder acts as a fast way to pick a level rather than a separate order system.
The action buttons
Join Bid and Join Ask place you on the near side of the market rather than crossing it.
Buy Mkt and Sell Mkt send a market order immediately.
Close exits the position on that contract.
Reverse closes and flips to the other side in one action.
Cancel All pulls your working orders.
Flatten All closes positions and cancels orders together.
Exits stay available when you are locked
Close, Reverse, Cancel All and Flatten All keep working during a lockout, the same as everywhere else in the platform. A lock stops you opening new exposure, never getting out of what you hold.
The same rules still apply
Orders sent from the ladder pass exactly the same checks as orders sent from the ticket. Your firm's contract cap, your personal risk settings, market hours and your account's allowed markets are all enforced identically.
The ladder is a faster way to send an order, not a way around anything.