This compensation option applies to PhD students whose contract ends between 1st January 2024 and 31st December 2024 and who have not previously received a COVID-19-related extension. So this is basically the last cohort of PhD students for whom compensation can be requested. The compensation only applies to those cases where it is deemed necessary.
It must be made clear why the adjustments made to the project in connection with COVID-19 needed to be revised to ensure completion within the original schedule. Where there is an appointment to a second- or third-funded project, this only applies if the delay can no longer be absorbed within the project itself.
Your own research institute will communicate the specific information and procedure on the compensation option.