Explain it only if the application asks for academic context or the course materially changes how your record will be interpreted.

One failed course does not automatically need a separate explanation, especially when the later record clearly shows recovery.

If the failure came during a documented disruption and the rest of your record improved substantially, a short factual note may help if there is an appropriate field.

Report the transcript accurately and avoid over-explaining unless the context is genuinely important. If useful, this guide on consulting application with a low GPA gives more detail.