If your order is not active, first check to make sure it is not in a "Paused" state. If your order has been "Paused", you will see a pause icon in the "Status" column and the Transmit button will be illuminated.
If you are attempting to trade outside of regular trading hours (RTH), you will need to configure your order to trade outside of RTH. The easiest way to configure a single order is to click on the Time in Force drop down and check the box that says "Fill Outside RTH". For more information on configuring your orders to trade outside of regular trading hours, please visit the IBKR Knowledge Base. The Regular Trading Hours session for any product can be found in the Description pop up window. In Classic TWS or Mosaic, right click on a symbol’s data line and select “Contract Info” followed by “Description” from the right click menu. If you do not see these options in the right click menu, expand it by left clicking on the small gray circle at the bottom. Once you have clicked "Description", scroll down to the Trading Hours section to see both the Regular Trading Hours and the Total Available Hours for that contract.
If you have further questions about the status of your order, please contact the IBKR Trade Group.