Is there a Mail box somewhere in terminal 1 to post my postcards? Help highly appreciated!

There is no post office at O’Hare but there are mail collection ​boxes scattered throughout the terminals: Terminal 1, Concourse B, Gate B9 Terminal 1, Concourse C, Gate C18 Terminal 3, Concourse H, Gate H1, Across from the Starbucks Terminal 3, Concourse L, Gate L2A, Across from Publican Tavern Terminal 5, Concourse M, Gate M8​

None BC of Covid19 they removed all mail boxes

Unfortunately I couldn’t find them at B9 I’m Terminal 1 and they told me they would be outside of security. But thank you for your help anyway!

There are drop boxes but you must have a postage stamp on your letter.