Confirm Submit Popup or Checkbox

I have a form that can't be edit after submit, and there are users who write in a support ticket to ask to amend the details they submitted.

I got 3 choices now,

  1. just a line above the submit button that tells users please check your details, it cant be edit after submit

  2. checkbox "I confirm I submitting the correct information and I can't edit them "

  3. popup "confirm submit? you cant edit the details after submit"

what's everyone thought?