Anas (May Allah be pleased with him) reported:
In the lifetime of the Messenger of Allah ﷺ, we used to perform two Rak'ah (optional prayer) after sunset before the Maghrib prayer. It was asked: "Did Messenger of Allah ﷺ perform them?" He replied: "He saw us performing it, but he neither ordered us to perform them nor did he forbid us from doing so."

[Muslim].

وعنه قال: كنا نصلي على عهد رسول الله ﷺ ركعتين بعد غروب الشمس قبل المغرب، فقيل: أكان رسول الله ﷺ صلاها؟ قال: كان يرانا نصليهما فلم يأمرنا ولم ينهنا". ((رواه مسلم)).