Email recruiting immediately. Missing the assessment deadline is serious, but a prompt explanation gives the firm the best chance to determine whether the link can be reopened.

Keep the message factual: you attempted to access the assessment, the link shows the window is closed, and you are asking whether an extension or reset is possible.

Do not wait another day hoping the link changes. Whether an exception is granted depends on the recruiting team and circumstances.

email them now. waiting only makes it worse.

I'd explain the deadline mistake clearly and ask if they can reopen.