You will receive the Quantum Computer code from Zero in one of the Q team endings. He directly gives it to you, so there is no way for you to miss this code once he gives it to you. There are multiple times when you will need this password so it is an important one to remember.
If you forget the password or don't want to wait, here is the code you need to access the Quantum Computer for Q team and activate the force quit box.
Quantum Computer Code = 38080832
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