'Aishah (May Allah be pleased with her) reported:
The Messenger of Allah ﷺ used to perform four Rak'ah of Duha prayer (at the forenoon) and would add to them whatever Allah wished.

[Muslim].

وعن عائشة رضي الله عنها قالت: كان رسول الله ﷺ يصلي الضحى أربعًا ويزيد ما شاء الله . ((رواه مسلم)).