Tax on bonus after change of residence

Is a bonus relating to former UK employment (throughout which UK tax resident) and which was paid/received after retiring, moving to France and becoming a French tax resident (per UK/France DTT) subject to UK Income Tax and UK Employee National Insurance or not? And, whether taxable or not in UK, must this income be reported to HMRC? If so, how and when?

Hi,
Please use the link below for guidance:
Tax on your UK income if you live abroad
Thank you